{"id":"CVE-2026-74696","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-74696","generatedAt":"2026-10-28T03:27:05.606Z","title":"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…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix TFO max_qlen accounting across reuseport migration\n\nA listener's TCP_FASTOPEN max_qlen stops being accurate and lets through\nfar more pending Fast Open requests than it was configured for.\n\nThis only shows up with SO_REUSEPORT listener migration, where closing a\nlistener hands its still-pending TFO children over to a surviving one.\n\nfastopenq.qlen is charged in tcp_fastopen_create_child() when the child\nis created and uncharged in reqsk_fastopen_remove() when the handshake\ncompletes.  The uncharge follows rsk_listener of the request the child\npoints at, and inet_reqsk_clone() has repointed the child at a new\nrequest owned by the new listener, so the ++ and the -- land on two\ndifferent sockets.  The new listener's qlen drifts negative and its\nlimit no longer binds.\n\nCharge the new listener during migration, like reqsk_queue_migrated()\nalready does for queue->young and queue->qlen.","published":"2026-08-22T16:16:44.000Z","lastModified":"2026-10-16T20:17:52.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":[],"epss":{"score":0.0049,"percentile":0.41851,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.49%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/585fc5247d14939a561056aa2addd9b7c2b1f670","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6e10ee56524a26b250229ad348637825646ddb88","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a0ab2ba83e35159d81cec830a92e885ecf8139be","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a66e869cf0c90c1e47ae75f72b6482acbfc808ff","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b6247e0f96bd825ffb2005257f6177b5e642dee6","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d974618b2097453778389d385e3741629c40e0a3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e98f0d80b9cccb5f828425d2004f9686e7d1ae24","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74696","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}