CVE-2026-80586: Linux kernel · mptcp: options: reset DSS fields in case of unexpected size
Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: options: reset DSS fields in case of unexpected size A remote peer could send a malformed DSS with a wrong size, followed by another DSS or MPC + Data. In this case, the first suboption will be ignored, but leaving some fields written, which could lead to inconsistency or access uninitialized data. Explicitly reset the fields that could have been modified in case of unexpected size.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80586 (opens in a new tab)
- git.kernel.org/stable/c/15e35fdad7a5576bf3f1c8d688877aeb5d1b506b (opens in a new tab)
- git.kernel.org/stable/c/192878df582c51d440bf7b91a15f297f29f2b596 (opens in a new tab)
- git.kernel.org/stable/c/1fade1b2ac5b1a4948e538fae7313bea57b5ac36 (opens in a new tab)
- git.kernel.org/stable/c/26dac5c9ffb20812b475fdf253eb04fab99cff3b (opens in a new tab)
- git.kernel.org/stable/c/27ed642a4e7e4b5df4b8522c72c457a67e052493 (opens in a new tab)
- git.kernel.org/stable/c/35772b4981f38ba8059372cde8753e8e477e98ec (opens in a new tab)
- git.kernel.org/stable/c/4e80eff5c1c893aca2ac1d202f0b256d2e52ecde (opens in a new tab)
- git.kernel.org/stable/c/b1256090816ec46011601e084be580731df58fc7 (opens in a new tab)