CVE-2026-23439
published 2026-04-03CVE-2026-23439: In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONFIG_IPV6…
PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.13%
2.9th percentile
In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.
The captured NULL deref crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
[...]
Call Trace:
genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)
[...]
netlink_rcv_skb (net/netlink/af_netlink.c:2550)
genl_rcv (net/netlink/genetlink.c:1219)
netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
netlink_sendmsg (net/netlink/af_netlink.c:1894)
__sock_sendmsg (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1))
__sys_sendto (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:2183 (discriminator 1))
__x64_sys_sendto (net/socket.c:2213 (discriminator 1) net/socket.c:2209 (discriminator 1) net/socket.c:2209 (discriminator 1))
do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
entry_SYSCALL_64_after_hwframe (net/arch/x86/entry/entry_64.S:130)
This patch makes udp_sock_create6 return -EPFNOSUPPORT instead, so
callers correctly take their error paths. There is only one caller of
the vulnerable function and only privileged users can trigger it.
Affected
63 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.19.10-1 (forky) | linux 6.19.10-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < dfc96ae0074cc47b5478a59e5aa19233e434243f | dfc96ae0074cc47b5478a59e5aa19233e434243f |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < 66117dbb3dbae82f86735bf727b1d59cc677afa1 | 66117dbb3dbae82f86735bf727b1d59cc677afa1 |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < ba7c9ddcdd077942b798979edb035207374d4096 | ba7c9ddcdd077942b798979edb035207374d4096 |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < a05a2149386f6dfb4245f522acdbef892acafc84 | a05a2149386f6dfb4245f522acdbef892acafc84 |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < 9f036aa0fe46c19e938f03d10e02c23f4fffae5e | 9f036aa0fe46c19e938f03d10e02c23f4fffae5e |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < 003343985f26dfefd0c94b1fe1316a2de74428b9 | 003343985f26dfefd0c94b1fe1316a2de74428b9 |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < 12aa4b73a67d95bc739995a2d6943aec2f9785c9 | 12aa4b73a67d95bc739995a2d6943aec2f9785c9 |
| linux | linux | >= fd384412e199b62c3ddaabd18dce86d0e164c5b9 < b3a6df291fecf5f8a308953b65ca72b7fc9e015d | b3a6df291fecf5f8a308953b65ca72b7fc9e015d |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.19.10-1 | 6.19.10-1 |
| linux | linux_kernel | >= 3.18.1 < 5.10.253 | 5.10.253 |
| linux | linux_kernel | >= 5.11 < 5.15.203 | 5.15.203 |
| linux | linux_kernel | >= 5.16 < 6.1.167 | 6.1.167 |
| linux | linux_kernel | >= 6.13 < 6.18.20 | 6.18.20 |
| linux | linux_kernel | >= 6.19 < 6.19.10 | 6.19.10 |
| linux | linux_kernel | >= 6.2 < 6.6.130 | 6.6.130 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_ubuntu7.1HIGH
vendor_redhat5.5MEDIUM
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Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-28·CVSS 7.1
CVE-2024-36898 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2026-07-28·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (HWE) vulnerabilities
Title: Linux kernel (HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local a
Ubuntu
Linux kernel (Azure CVM) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (Azure CVM) vulnerabilities
Title: Linux kernel (Azure CVM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A l
Ubuntu
Linux kernel (Azure FIPS) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (Azure FIPS) vulnerabilities
Title: Linux kernel (Azure FIPS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A
Ubuntu
Linux kernel (Azure CVM) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-43129 [LOW] Linux kernel (Azure CVM) vulnerabilities
Title: Linux kernel (Azure CVM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A l
Ubuntu
Linux kernel (Azure CVM) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 7.1
CVE-2024-36898 [HIGH] Linux kernel (Azure CVM) vulnerabilities
Title: Linux kernel (Azure CVM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cac
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local a
Ubuntu
Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A loca
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-43129 [LOW] Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A loca
Ubuntu
Linux kernel (IBM) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 7.1
CVE-2026-46187 [HIGH] Linux kernel (IBM) vulnerabilities
Title: Linux kernel (IBM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 7.1
CVE-2026-46187 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local
Ubuntu
Linux kernel (NVIDIA Tegra) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 7.1
CVE-2026-46187 [HIGH] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local attacke
Ubuntu
Linux kernel (GCP FIPS) vulnerabilities
vendor_ubuntu·2026-07-21·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (GCP FIPS) vulnerabilities
Title: Linux kernel (GCP FIPS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A lo
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-21·CVSS 7.1
CVE-2024-36898 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local
Ubuntu
Linux kernel (NVIDIA Tegra) vulnerabilities
vendor_ubuntu·2026-07-21·CVSS 7.1
CVE-2024-36898 [HIGH] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-20·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local attacke
Red Hat
kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
vendor_redhat·2026-04-03·CVSS 5.5
CVE-2026-23439 [MEDIUM] CWE-476 kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.
The captured NULL deref crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
[...]
Call Trace:
genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:12
Debian
CVE-2026-23439: linux - In the Linux kernel, the following vulnerability has been resolved: udp_tunnel:...
vendor_debian·2026
CVE-2026-23439 CVE-2026-23439: linux - In the Linux kernel, the following vulnerability has been resolved: udp_tunnel:...
In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0 (success) without actually creating a socket. Callers such as fou_create() then proceed to dereference the uninitialized socket pointer, resulting in a NULL pointer dereference. The captured NULL deref crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764) [...] Call Trace: genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114) genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209) [...] netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/gen
VulDB
Linux Kernel up to 7.0-rc4 net/ipv4/fou_core.c udp_sock_create6 null pointer dereference (EUVD-2026-18680 / Nessus ID 311783)
vuldb·2026-07-17·CVSS 5.5
CVE-2026-23439 [MEDIUM] Linux Kernel up to 7.0-rc4 net/ipv4/fou_core.c udp_sock_create6 null pointer dereference (EUVD-2026-18680 / Nessus ID 311783)
A vulnerability was found in Linux Kernel up to 7.0-rc4. It has been rated as critical. The impacted element is the function udp_sock_create6 of the file net/ipv4/fou_core.c. Performing a manipulation results in null pointer dereference.
This vulnerability is identified as CVE-2026-23439. The attack can only be performed from the local network. There is not any exploit available.
Upgrading the affected component is advised.
OSV
CVE-2026-23439: In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONF
osv·2026-04-03
CVE-2026-23439 CVE-2026-23439: In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONF
In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0 (success) without actually creating a socket. Callers such as fou_create() then proceed to dereference the uninitialized socket pointer, resulting in a NULL pointer dereference. The captured NULL deref crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764) [...] Call Trace: genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114) genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209) [...] netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/gen
GHSA
GHSA-8f9w-9r3m-xjvx: In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CO
ghsa_unreviewed·2026-04-03
CVE-2026-23439 GHSA-8f9w-9r3m-xjvx: In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CO
In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.
The captured NULL deref crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
[...]
Call Trace:
genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)
[...]
netlink_rcv_skb (net/netlink/af_netlink.c:2550)
genl_rcv (net/netlink
No detection rules found.
No public exploits indexed.
Wiz
CVE-2026-23439 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz
CVE-2026-23439 CVE-2026-23439 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-23439 :
Linux Kernel vulnerability analysis and mitigation
In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.
The captured NULL deref crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
[...]
Call Trace: genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)
[..
Bugzilla
CVE-2026-23439 kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
bugzilla·2026-04-03·CVSS 5.5
CVE-2026-23439 [MEDIUM] CVE-2026-23439 kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
CVE-2026-23439 kernel: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
In the Linux kernel, the following vulnerability has been resolved:
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.
The captured NULL deref crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
[...]
Call Trace:
genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
genl_rcv_msg (net/netlink/genetlink.c:1194 net/netl
https://git.kernel.org/stable/c/003343985f26dfefd0c94b1fe1316a2de74428b9https://git.kernel.org/stable/c/12aa4b73a67d95bc739995a2d6943aec2f9785c9https://git.kernel.org/stable/c/66117dbb3dbae82f86735bf727b1d59cc677afa1https://git.kernel.org/stable/c/9f036aa0fe46c19e938f03d10e02c23f4fffae5ehttps://git.kernel.org/stable/c/a05a2149386f6dfb4245f522acdbef892acafc84https://git.kernel.org/stable/c/b3a6df291fecf5f8a308953b65ca72b7fc9e015dhttps://git.kernel.org/stable/c/ba7c9ddcdd077942b798979edb035207374d4096https://git.kernel.org/stable/c/dfc96ae0074cc47b5478a59e5aa19233e434243fhttps://cert-portal.siemens.com/productcert/html/ssa-019113.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-082556.html
2026-04-03
Published