CVE-2026-64007
published 2026-07-19CVE-2026-64007: In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: refresh tcphdr after skb_ensure_writable synproxy_tstamp_adjust()…
PriorityP355critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.51%
42.0th percentile
In the Linux kernel, the following vulnerability has been resolved:
netfilter: synproxy: refresh tcphdr after skb_ensure_writable
synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
and then patches the TCP checksum via inet_proto_csum_replace4() on
the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and
ipv6_synproxy_hook() obtain that pointer with skb_header_pointer()
before calling in, so it may either alias skb->head directly or
point at the caller's on-stack _tcph buffer.
Between obtaining the pointer and using it, the function calls
skb_ensure_writable(skb, optend), which on a cloned or non-linear
skb invokes pskb_expand_head() and frees the old skb->head. After
that point the cached th is stale:
caller (ipv[46]_synproxy_hook)
th = skb_header_pointer(skb, ..., &_tcph)
synproxy_tstamp_adjust(skb, protoff, th, ...)
skb_ensure_writable(skb, optend)
pskb_expand_head() /* kfree(old skb->head) */
...
inet_proto_csum_replace4(&th->check, ...)
/* writes into freed head, or
into the caller's stack copy
leaving the on-wire checksum
stale */
The option bytes are written through skb->data and are fine; only
the checksum update goes through th and so lands in the wrong
place. The result is either a write into freed slab memory or a
packet leaving with a checksum that does not match its payload.
Fix by re-deriving th from skb->data + protoff immediately after
skb_ensure_writable() succeeds, so the subsequent checksum update
targets the linear, writable header.
Affected
53 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < 9902a1058992de5d95656b64a3bd95c077f7ba2c | 9902a1058992de5d95656b64a3bd95c077f7ba2c |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < d3019c61799adc21811af4b521f11f3dc77f8e04 | d3019c61799adc21811af4b521f11f3dc77f8e04 |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < dd206819f210522579010d889d45a9530bb494bc | dd206819f210522579010d889d45a9530bb494bc |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < af2c22ccb1f621aff487ff47a040e38e058541e7 | af2c22ccb1f621aff487ff47a040e38e058541e7 |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < c7f945f7da097245a2f8ed7775ce48421047ee96 | c7f945f7da097245a2f8ed7775ce48421047ee96 |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < f0fea2b6d5453a11ad11713bbf37561b9b3a7edf | f0fea2b6d5453a11ad11713bbf37561b9b3a7edf |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < a91887a5b6ee4b98dfbf1db657ed2b879430149e | a91887a5b6ee4b98dfbf1db657ed2b879430149e |
| linux | linux | >= 48b1de4c110a7afa4b85862f6c75af817db26fad < 92170e6afe927ab2792a3f71902845789c8e31b1 | 92170e6afe927ab2792a3f71902845789c8e31b1 |
| ubuntu | linux | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-aws-6.8 | — | — |
| ubuntu | linux-aws-fips | — | — |
| ubuntu | linux-azure | — | — |
| ubuntu | linux-azure-6.8 | — | — |
| ubuntu | linux-azure-7.0 | — | — |
| ubuntu | linux-azure-fde | — | — |
| ubuntu | linux-azure-fde-6.8 | — | — |
| ubuntu | linux-azure-fips | — | — |
| ubuntu | linux-fips | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gcp-5.15 | — | — |
| ubuntu | linux-gcp-6.8 | — | — |
| ubuntu | linux-gcp-7.0 | — | — |
| ubuntu | linux-gcp-fips | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
vendor_ubuntu9.4CRITICAL
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CVE-2026-53354 [CRITICAL] Linux kernel (FIPS) vulnerabilities
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It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
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CVE-2026-53354 [CRITICAL] Linux kernel (NVIDIA Tegra) vulnerabilities
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Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
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Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
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Summary: Several security issues were fixed in the Linux kernel.
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through the invalidated translation were globally observed. A local
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so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
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CVE-2025-10263 [CRITICAL] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
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- Network drivers;
- TCM subsystem;
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CVE-2026-63886 [CRITICAL] Linux kernel (AWS FIPS) vulnerabilities
Title: Linux kernel (AWS FIPS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
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Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-09-29·CVSS 9.1
CVE-2026-64191 [CRITICAL] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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)
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Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
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(CVE-2026-53131, CVE-2026-53186, CVE-2026-53216, CVE-2026-53221,
CVE-2026-53355, CVE-2026-63886, CVE-2026-63887, CVE-2026-63888,
CVE-2026-63912, CVE-2026-63922, CVE-2026-63924, CVE-2026-63984,
CVE-2026-63992, CVE-2026-63993, CVE-2026-63994, CVE-2026-64000,
CVE-2026-64007, CVE-2026-64091)
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CVE-2026-63912 [CRITICAL] Linux kernel (IBM) vulnerabilities
Title: Linux kernel (IBM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- InfiniBand drivers;
- Network drivers;
- TCM subsystem;
- exFAT file system;
- Network file system (NFS) c
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vendor_ubuntu·2026-09-24·CVSS 9.1
CVE-2026-63886 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- InfiniBand drivers;
- Network drivers;
- TCM subsystem;
- B.A.T.M.A.N. meshing protocol;
- HSR network protocol;
Ubuntu
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vendor_ubuntu·2026-09-24·CVSS 9.1
CVE-2026-63912 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- InfiniBand drivers;
- Network drivers;
- TCM subsystem;
- exFAT file system;
- Network file system (NFS) client;
Ubuntu
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vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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 di
Ubuntu
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CVE-2026-53358 [CRITICAL] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
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Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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 disc
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
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CVE-2026-64234 [HIGH] 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 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:
- x86 platform drivers;
- Cryptographic API;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x
Ubuntu
Linux kernel (NVIDIA BaseOS) vulnerabilities
vendor_ubuntu·2026-08-20·CVSS 7.0
CVE-2026-64109 [HIGH] Linux kernel (NVIDIA BaseOS) vulnerabilities
Title: Linux kernel (NVIDIA BaseOS) 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:
- x86 platform drivers;
- Cryptographic API;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UM
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-28·CVSS 7.0
CVE-2026-64231 [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:
- x86 platform drivers;
- Cryptographic API;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x86 archit
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-07-24·CVSS 2.0
CVE-2026-64107 [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)
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:
- x86 platfor
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 7.0
CVE-2026-64107 [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:
- x86 platform drivers;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x86 architecture;
- Block layer
Red Hat
kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable
vendor_redhat·2026-07-19·CVSS 9.8
CVE-2026-64007 [CRITICAL] CWE-825 kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable
kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable
In the Linux kernel, the following vulnerability has been resolved:
netfilter: synproxy: refresh tcphdr after skb_ensure_writable
synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
and then patches the TCP checksum via inet_proto_csum_replace4() on
the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and
ipv6_synproxy_hook() obtain that pointer with skb_header_pointer()
before calling in, so it may either alias skb->head directly or
point at the caller's on-stack _tcph buffer.
Between obtaining the pointer and using it, the function calls
skb_ensure_writable(skb, optend), which on a cloned or non-linear
skb invokes pskb_expand_head() and frees the old skb->head. After
that point the cached th i
GHSA
In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: refresh tcphdr after skb_ensure_writable synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
ghsa_unreviewed·2026-07-19
CVE-2026-64007 [CRITICAL] In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: refresh tcphdr after skb_ensure_writable synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
In the Linux kernel, the following vulnerability has been resolved:
netfilter: synproxy: refresh tcphdr after skb_ensure_writable
synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
and then patches the TCP checksum via inet_proto_csum_replace4() on
the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and
ipv6_synproxy_hook() obtain that pointer with skb_header_pointer()
before calling in, so it may either alias skb->head directly or
point at the caller's on-stack _tcph buffer.
Between obtaining the pointer and using it, the function calls
skb_ensure_writable(skb, optend), which on a cloned or non-linear
skb invokes pskb_expand_head() and frees the old skb->head. After
that point the cached th is stale:
caller (ipv[46]_synproxy_hook)
th = skb_header_pointer(skb
VulDB
Linux Kernel up to 7.0.11 Synproxy synproxy_tstamp_adjust use after free
vuldb·2026-07-19
CVE-2026-64007 Linux Kernel up to 7.0.11 Synproxy synproxy_tstamp_adjust use after free
A vulnerability was found in Linux Kernel up to 7.0.11 and classified as very critical. Impacted is the function synproxy_tstamp_adjust of the component Synproxy. Executing a manipulation can lead to use after free.
This vulnerability is registered as CVE-2026-64007. It is possible to launch the attack remotely. No exploit is available.
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/92170e6afe927ab2792a3f71902845789c8e31b1https://git.kernel.org/stable/c/9902a1058992de5d95656b64a3bd95c077f7ba2chttps://git.kernel.org/stable/c/a91887a5b6ee4b98dfbf1db657ed2b879430149ehttps://git.kernel.org/stable/c/af2c22ccb1f621aff487ff47a040e38e058541e7https://git.kernel.org/stable/c/c7f945f7da097245a2f8ed7775ce48421047ee96https://git.kernel.org/stable/c/d3019c61799adc21811af4b521f11f3dc77f8e04https://git.kernel.org/stable/c/dd206819f210522579010d889d45a9530bb494bchttps://git.kernel.org/stable/c/f0fea2b6d5453a11ad11713bbf37561b9b3a7edf
2026-07-19
Published