CVE-2026-5947
SIG(0) validation during query flood may lead to undefined behavior
HIGH 7.5
En bref
- Source
- NVD
- EPSS
- EPSS 1.39 % · centile 72 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- isc
- Statut NVD
- Modified
Description
Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.
Faiblesses (CWE)
- CWE-362 — Situation de compétition
- CWE-416 — Utilisation après libération
- CWE-367 — Situation de compétition TOCTOU
Références
- https://kb.isc.org/docs/cve-2026-5947
- https://downloads.isc.org/isc/bind9/9.20.23
- https://downloads.isc.org/isc/bind9/9.21.22
- https://access.redhat.com/security/cve/CVE-2026-5947
- https://bugzilla.redhat.com/show_bug.cgi?id=2479772
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5947.json
- https://access.redhat.com/errata/RHSA-2026:7412
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | isc |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-officer@isc.org (Secondary) |
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Références européennes
- ENISA EUVD · EUVD-2026-31110
- GCVE · GCVE-0-2026-5947
Avis du CERT-FR
- CERTFR-2026-AVI-0626 — Multiples vulnérabilités dans ISC BIND · cert.ssi.gouv.fr
Configurations affectées (CPE NVD)
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*≥ 9.20.0 < 9.20.23cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*≥ 9.21.0 < 9.21.22
Produits affectés
| Produit | Versions |
|---|---|
| ISC · BIND 9 | affected 9.20.0 ≤ 9.20.22 ; affected 9.21.0 ≤ 9.21.21 ; affected 9.20.9-S1 ≤ 9.20.22-S1 ; unaffected 9.18.28 ≤ 9.18.49 ; unaffected 9.18.28-S1 ≤ 9.18.49-S1 |
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 |