netfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check (Linux Linux)

CVE-2026-63913
HIGH 8.2

En bref

Source
NVD
EPSS
EPSS 0.97 % · centile 62 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check An unintended behavior in the TCP conntrack state machine allows a connection to be forced into the CLOSE state using an RST packet with an invalid sequence number. Specifically, after a SYN packet is observed, an RST with an invalid SEQ can transition the conntrack entry to TCP_CONNTRACK_CLOSE, regardless of whether the RST corresponds to the expected reply direction. The relevant code path assumes the RST is a response to an outgoing SYN, but does not validate packet direction or ensure that a matching SYN was actually sent in the opposite direction. As a result, a crafted packet sequence consisting of a SYN followed by an invalid-sequence RST can prematurely terminate an active NAT entry. This makes connection teardown easier than intended. So, tighten the state transition logic to ensure that RST-triggered CLOSE transitions only occur when the RST is a valid response to a previously observed SYN in the correct direction.

Faiblesses (CWE)

  • CWE-20 — Validation d'entrée incorrecte

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1HIGH 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HLinux
CVSS 3.1HIGH 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < 2006979a15af5404bf932a325357683c0bac1656 ; affected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < 6476c17d536dbd321c073242e762ddb2713a1238 ; affected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < f5547bebc416d56f56fb5b86dc20aabfa42165a0 ; affected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < 2bb6d82b586ea5a4cb73bbdd6b7432e96096bc77 ; affected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < f206def4e86d810f927ba1d8e322ea72b29bce58 ; affected 9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1 < b98ab51c45c5608a1c19ce7fd17a3032469bb83f
Linux · Linuxaffected 2.6.15 ; unaffected 0 < 2.6.15 ; unaffected 5.10.259 ≤ 5.10.* ; unaffected 5.15.210 ≤ 5.15.* ; unaffected 6.1.176 ≤ 6.1.* ; unaffected 6.6.143 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD