CVE-2026-53070
published 2026-06-24CVE-2026-53070: In the Linux kernel, the following vulnerability has been resolved: sctp: disable BH before calling udp_tunnel_xmit_skb() udp_tunnel_xmit_skb() /…
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.35%
27.4th percentile
In the Linux kernel, the following vulnerability has been resolved:
sctp: disable BH before calling udp_tunnel_xmit_skb()
udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with
BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to
tunnel xmit functions"), on the path:
udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit()
dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU.
Without local_bh_disable(), the context may move between CPUs, which can
break the inc/dec pairing. This may lead to incorrect recursion level
detection and cause packets to be dropped in ip(6)_tunnel_xmit() or
__dev_queue_xmit().
Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths.
In my testing, after enabling the SCTP over UDP:
# ip net exec ha sysctl -w net.sctp.udp_port=9899
# ip net exec ha sysctl -w net.sctp.encap_port=9899
# ip net exec hb sysctl -w net.sctp.udp_port=9899
# ip net exec hb sysctl -w net.sctp.encap_port=9899
# ip net exec ha iperf3 -s
- without this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender
[ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver
- with this patch:
# ip net exec hb iperf3 -c 192.168.0.1 --sctp
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender
[ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver
Affected
15 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= 046c052b475e7119b6a30e3483e2888fc606a2f8 < be3bfcb34bda04f6a350710db471d4133f950f2c | be3bfcb34bda04f6a350710db471d4133f950f2c |
| linux | linux | >= 046c052b475e7119b6a30e3483e2888fc606a2f8 < 0de7db2eb27e82b983157016fa604b1ba664ae5f | 0de7db2eb27e82b983157016fa604b1ba664ae5f |
| linux | linux | >= 046c052b475e7119b6a30e3483e2888fc606a2f8 < 790093245e35040c2adb15f48970020425aa3f47 | 790093245e35040c2adb15f48970020425aa3f47 |
| linux | linux | >= 046c052b475e7119b6a30e3483e2888fc606a2f8 < 2cd7e6971fc2787408ceef17906ea152791448cf | 2cd7e6971fc2787408ceef17906ea152791448cf |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 5.11 < 6.12.95 | 6.12.95 |
| linux | linux_kernel | >= 6.13 < 6.18.37 | 6.18.37 |
| linux | linux_kernel | >= 6.19 < 7.0.10 | 7.0.10 |
| ubuntu | linux | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gke | — | — |
| ubuntu | linux-hwe-7.0 | — | — |
| ubuntu | linux-oem-7.0 | — | — |
| ubuntu | linux-realtime | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_ubuntu7.0HIGH
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Linux Kernel up to 7.0.9 sctp udp_tunnel_xmit_skb recursion
vuldb·2026-06-24
CVE-2026-53070 [CRITICAL] Linux Kernel up to 7.0.9 sctp udp_tunnel_xmit_skb recursion
A vulnerability classified as critical was found in Linux Kernel up to 7.0.9. The affected element is the function udp_tunnel_xmit_skb of the component sctp. Such manipulation leads to uncontrolled recursion.
This vulnerability is listed as CVE-2026-53070. The attack must be carried out from within the local network. There is no available exploit.
Upgrading the affected component is advised.
GHSA
In the Linux kernel, the following vulnerability has been resolved: sctp: disable BH before calling udp_tunnel_xmit_skb() udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with BH d
ghsa_unreviewed·2026-06-24
CVE-2026-53070 In the Linux kernel, the following vulnerability has been resolved: sctp: disable BH before calling udp_tunnel_xmit_skb() udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with BH d
In the Linux kernel, the following vulnerability has been resolved:
sctp: disable BH before calling udp_tunnel_xmit_skb()
udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with
BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to
tunnel xmit functions"), on the path:
udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit()
dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU.
Without local_bh_disable(), the context may move between CPUs, which can
break the inc/dec pairing. This may lead to incorrect recursion level
detection and cause packets to be dropped in ip(6)_tunnel_xmit() or
__dev_queue_xmit().
Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths.
In my testing, after enabling the SCTP over UDP:
# ip net exec ha sysctl -w
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-07-20·CVSS 7.0
CVE-2026-46108 [HIGH] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
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)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- PSP security protocol;
- ARM64 architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Intel NPU Driver;
- DRBD D
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2026-07-20·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 the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TC
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-20·CVSS 7.0
CVE-2026-46113 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
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)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- PSP security protocol;
- ARM64 architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Intel NPU Driver;
- DRBD Distrib
Red Hat
kernel: sctp: disable BH before calling udp_tunnel_xmit_skb()
vendor_redhat·2026-06-24·CVSS 5.5
CVE-2026-53070 [MEDIUM] CWE-821 kernel: sctp: disable BH before calling udp_tunnel_xmit_skb()
kernel: sctp: disable BH before calling udp_tunnel_xmit_skb()
A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) over User Datagram Protocol (UDP) implementation. An issue with managing the transmission context across different processing units could lead to incorrect recursion level detection. This can cause network packets to be dropped, resulting in a Denial of Service (DoS) for affected systems.
Package: kernel (Red Hat Enterprise Linux 10) - Fix deferred
Package: kernel (Red Hat Enterprise Linux 6) - Out of support scope
Package: kernel (Red Hat Enterprise Linux 7) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Fix deferred
Package: kernel-rt (Red Hat Enterprise Linux 8
No detection rules found.
No public exploits indexed.
2026-06-24
Published