CVE-2026-74696tcp: fix TFO max_qlen accounting across reuseport migration
- 7.5HighCVSS base score
- 0.49%Exploitation in 30 daysEPSS · top 57% 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: tcp: fix TFO max_qlen accounting across reuseport migration A listener's TCP_FASTOPEN max_qlen stops being accurate and lets through far more pending Fast Open requests than it was configured for. This only shows up with SO_REUSEPORT listener migration, where closing a listener hands its still-pending TFO children over to a surviving one. fastopenq.qlen is charged in tcp_fastopen_create_child() when the child is created and uncharged in reqsk_fastopen_remove() when the handshake completes. The uncharge follows rsk_listener of the request the child points at, and inet_reqsk_clone() has repointed the child at a new request owned by the new listener, so the ++ and the -- land on two different sockets. The new listener's qlen drifts negative and its limit no longer binds. Charge the new listener during migration, like reqsk_queue_migrated() already does for queue->young and queue->qlen.
Timeline
ID reserved
By Linux
- 7 days later
· 7 days later
Published
- 55 days later
· 55 days 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 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Received | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.49% · top 57% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < e98f0d80b9cccb5f828425d2004f9686e7d1ae24
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < b6247e0f96bd825ffb2005257f6177b5e642dee6
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < 585fc5247d14939a561056aa2addd9b7c2b1f670
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < 6e10ee56524a26b250229ad348637825646ddb88
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < a66e869cf0c90c1e47ae75f72b6482acbfc808ff
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < d974618b2097453778389d385e3741629c40e0a3
- affected 54b92e84193749c9968aff2dd46e3b0f42643e18 – < a0ab2ba83e35159d81cec830a92e885ecf8139be
- affected 5.14
- unaffected < 5.14
- unaffected 5.15.216 – ≤ 5.15.*
- unaffected 6.1.183 – ≤ 6.1.*
- unaffected 6.6.152 – ≤ 6.6.*
- unaffected 6.12.104 – ≤ 6.12.*
- unaffected 6.18.45 – ≤ 6.18.*
- unaffected 7.1.9 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References7
- https://git.kernel.org/stable/c/e98f0d80b9cccb5f828425d2004f9686e7d1ae24 (opens in a new tab)
- https://git.kernel.org/stable/c/b6247e0f96bd825ffb2005257f6177b5e642dee6 (opens in a new tab)
- https://git.kernel.org/stable/c/585fc5247d14939a561056aa2addd9b7c2b1f670 (opens in a new tab)
- https://git.kernel.org/stable/c/6e10ee56524a26b250229ad348637825646ddb88 (opens in a new tab)
- https://git.kernel.org/stable/c/a66e869cf0c90c1e47ae75f72b6482acbfc808ff (opens in a new tab)
- https://git.kernel.org/stable/c/d974618b2097453778389d385e3741629c40e0a3 (opens in a new tab)
- https://git.kernel.org/stable/c/a0ab2ba83e35159d81cec830a92e885ecf8139be (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-2026-64383 (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-2026-74696)Record last updated .