CVE-2026-74262kcm: use WRITE_ONCE() when changing lower socket callbacks
- 7.8HighCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: kcm: use WRITE_ONCE() when changing lower socket callbacks kcm_attach() replaces a live lower TCP socket's sk_data_ready and sk_write_space callbacks with KCM handlers, and kcm_unattach() restores them later. Those callback-pointer updates are still plain stores even though the same fields can be read and invoked concurrently on other CPUs. If another CPU observes an older callback snapshot after the live field has already been restored, callback execution can run with a mismatched target and sk_user_data state, leading to stale or misdirected wakeups. Use WRITE_ONCE() for the callback replacement and restore operations so these shared callback fields follow the same visibility contract already established by the earlier 4022 fixes.
Timeline
ID reserved
By Linux
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < 0cb3e2f40679032c1aa2186280a86e5ead0161ee
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < fa26e4606aed0f7fe793c325506adeda1d847a43
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < b4ccd6eef671d7c44a30123cd29f3acf3de8468e
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < b8c90823cdfb5f3d22f261aeb3e9066612853c36
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < 11faefd11ce2448bac7279ab302dd1954a6547fe
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < f01fb6138f8eb606b56ce9158e2d8b72352c53f4
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < 9684fff87124b201e11dea01ded9173025359a0f
- affected ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 – < 47186409c092cd7dd70350999186c700233e854d
- affected 4.6
- unaffected < 4.6
- unaffected 5.10.261 – ≤ 5.10.*
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.97 – ≤ 6.12.*
- unaffected 6.18.40 – ≤ 6.18.*
- unaffected 7.1.5 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References8
- https://git.kernel.org/stable/c/0cb3e2f40679032c1aa2186280a86e5ead0161ee (opens in a new tab)
- https://git.kernel.org/stable/c/fa26e4606aed0f7fe793c325506adeda1d847a43 (opens in a new tab)
- https://git.kernel.org/stable/c/b4ccd6eef671d7c44a30123cd29f3acf3de8468e (opens in a new tab)
- https://git.kernel.org/stable/c/b8c90823cdfb5f3d22f261aeb3e9066612853c36 (opens in a new tab)
- https://git.kernel.org/stable/c/11faefd11ce2448bac7279ab302dd1954a6547fe (opens in a new tab)
- https://git.kernel.org/stable/c/f01fb6138f8eb606b56ce9158e2d8b72352c53f4 (opens in a new tab)
- https://git.kernel.org/stable/c/9684fff87124b201e11dea01ded9173025359a0f (opens in a new tab)
- https://git.kernel.org/stable/c/47186409c092cd7dd70350999186c700233e854d (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-59409 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-74262)Record last updated .