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CVE record · CVE-2026-80585

mptcp: fastopen: only mark MPTFO subflows with SYN data

CVSS 9.4 CriticalCriticalEPSS 0.0031 · 24th percentile

Critical, because:

  • CVSS score 9.4: 9.0 or more.

How we decide what’s critical

Published by the CVE Program (CNA: Linux) at 26 Aug 2026, 14:37 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
VendorProductVersions
Linux Linux
  • affected 36b122baf6a8bd46b4a591f12f4ed17b22257408 to before f75f174edc865738522e514d042cf5627f084859 git
  • affected 36b122baf6a8bd46b4a591f12f4ed17b22257408 to before fca7e444c04689fe4cc6b56f2725f804a4bb1ef9 git
  • affected 36b122baf6a8bd46b4a591f12f4ed17b22257408 to before 75e564b2ced1cc3d9a8904c7d2d2bb448fffb8b5 git
  • affected 36b122baf6a8bd46b4a591f12f4ed17b22257408 to before 72b4a0c51a4b550d40301d60a366b429b8c8e78d git
  • affected 36b122baf6a8bd46b4a591f12f4ed17b22257408 to before e00b63056fb4f261455b3e5df5268a1f8ce47a87 git
Other versions: unaffected
Linux Linux
  • affected 6.2
  • unaffected before 6.2 semver
  • unaffected 6.6.153 to 6.6.*, inclusive semver
  • unaffected 6.12.105 to 6.12.*, inclusive semver
  • unaffected 6.18.46 to 6.18.*, inclusive semver
  • unaffected 7.1.10 to 7.1.*, inclusive semver
  • unaffected 7.2 to *, inclusive original_commit_for_fix
Other versions: affected
Identifiers
CVE-2026-80585
CNA
Linux
Tags
Published
26 Aug 2026
Updated
16 Oct 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

ScoreRatingCVSSVectorSource
9.4 Critical 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H CNA (Linux)
  • CISA KEV Not listed.
  • EPSS 0.0031, the 24th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 26 Aug 2026. New records show when each source confirmed them.

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.