VulnerabilityPublished 25 Jun 2026Updated 6 Nov 2026

CVE-2026-53236: Linux kernel · tcp: restrict SO_ATTACH_FILTER to priv users

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in ede69b8f6670600e534591664584f810d7c385f9 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in ede69b8f6670600e534591664584f810d7c385f9, ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba, c68517a3e18e20997808821c5559d0cba4d776c1 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ede69b8f6670600e534591664584f810d7c385f9	Fixed in ede69b8f6670600e534591664584f810d7c385f9
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba	Fixed in ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < c68517a3e18e20997808821c5559d0cba4d776c1	Fixed in c68517a3e18e20997808821c5559d0cba4d776c1
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 3747de241a66ef2c7032d2cc2b826a47c5fa0f6a	Fixed in 3747de241a66ef2c7032d2cc2b826a47c5fa0f6a
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 82b3e7ce10c53fc12aab8904745603efc74f8c07	Fixed in 82b3e7ce10c53fc12aab8904745603efc74f8c07
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5d39580f68e6ddeedd15e587282207489dfb3da2	Fixed in 5d39580f68e6ddeedd15e587282207489dfb3da2

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.

References

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