CVE-2026-53236
Published Jun 25, 2026
Modified Jun 30, 2026
Description
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.
EPSS — Exploit Prediction
0.0018
Probability of exploitation
0.08%
Percentile rank
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
References
Other References
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
Frequently Asked Questions
What is CVE-2026-53236? +
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.
How do I check if I'm vulnerable to CVE-2026-53236? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.