CVE-2026-31476
ksmbd: do not expire session on binding failure
HIGH 8.2
At a glance
- Source
- NVD
- EPSS
- EPSS 0.50 % · percentile 43 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: do not expire session on binding failure When a multichannel session binding request fails (e.g. wrong password), the error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED. However, during binding, sess points to the target session looked up via ksmbd_session_lookup_slowpath() -- which belongs to another connection's user. This allows a remote attacker to invalidate any active session by simply sending a binding request with a wrong password (DoS). Fix this by skipping session expiration when the failed request was a binding attempt, since the session does not belong to the current connection. The reference taken by ksmbd_session_lookup_slowpath() is still correctly released via ksmbd_user_session_put().
References
- https://git.kernel.org/stable/c/4642ea35c03cf3d3558c009df4757cdb7af3f82d
- https://git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6
- https://git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc
- https://git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3
- https://git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f
- https://git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb
- https://git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | Linux |
| CVSS 3.1 | HIGH 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-24831
- GCVE · GCVE-0-2026-31476
CERT-FR advisories
- CERTFR-2026-AVI-1286 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1093 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0985 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0547 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0519 — Multiples vulnérabilités dans Microsoft Azure Linux · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.15.1 < 6.1.168cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.131cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.80cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.21cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.11cpe:2.3:o:linux:linux_kernel:5.15:-:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected f5a544e3bab78142207e0242d22442db85ba1eff < 4642ea35c03cf3d3558c009df4757cdb7af3f82d ; affected f5a544e3bab78142207e0242d22442db85ba1eff < f5300690c23c5ac860499bb37dbc09cf43fd62e6 ; affected f5a544e3bab78142207e0242d22442db85ba1eff < 6fafc4c4238e538969f1375f9ecdc6587c53f1cc ; affected f5a544e3bab78142207e0242d22442db85ba1eff < 1d1888b4a7aec518b707f6eca0bf08992c0e8da3 ; affected f5a544e3bab78142207e0242d22442db85ba1eff < a897064a457056acb976e20e3007cdf553de340f ; affected f5a544e3bab78142207e0242d22442db85ba1eff < e0e5edc81b241c70355217de7e120c97c3429deb |
| Linux · Linux | affected 5.15 ; unaffected 0 < 5.15 ; unaffected 5.15.209 ≤ 5.15.* ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.131 ≤ 6.6.* ; unaffected 6.12.80 ≤ 6.12.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |