tcp: restrict SO_ATTACH_FILTER to priv users
In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.
02 / AFFECTED SOFTWARE
Affected packages
1371 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/3747de241a66ef2c7032d2cc2b826a47c5fa0f6a
- https://git.kernel.org/stable/c/5d39580f68e6ddeedd15e587282207489dfb3da2
- https://git.kernel.org/stable/c/82b3e7ce10c53fc12aab8904745603efc74f8c07
- https://git.kernel.org/stable/c/c68517a3e18e20997808821c5559d0cba4d776c1
- https://git.kernel.org/stable/c/ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba
- https://git.kernel.org/stable/c/ede69b8f6670600e534591664584f810d7c385f9
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53236.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-53236