CVE-2026-5946
Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.70%
- Percentil entre todas las CVEs puntuadas: 76
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
Vector CVSS AV:N/AC:L/PR:N sin requerimiento de interacción; acceso remoto a BIND DNS. Solicitudes DNS especialmente crafted causan fallos de aserción (DoS). CWE-20, CWE-125 (buffer over-read), CWE-617 (assertion failure) sustentan impacto de disponibilidad.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-20, CWE-125, CWE-617, CWE-754, CWE-843
- CWE-1287
Referencias
- https://downloads.isc.org/isc/bind9/9.18.49
- https://downloads.isc.org/isc/bind9/9.20.23
- https://downloads.isc.org/isc/bind9/9.21.22
- https://kb.isc.org/docs/cve-2026-5946
- https://access.redhat.com/errata/RHSA-2026:20334
- https://access.redhat.com/errata/RHSA-2026:23360
- https://access.redhat.com/errata/RHSA-2026:24338
- https://access.redhat.com/errata/RHSA-2026:24339
- https://access.redhat.com/errata/RHSA-2026:24367
- https://access.redhat.com/errata/RHSA-2026:24368
- https://access.redhat.com/errata/RHSA-2026:55441
- https://access.redhat.com/errata/RHSA-2026:57189
- https://access.redhat.com/errata/RHSA-2026:60383
- https://access.redhat.com/errata/RHSA-2026:62549
- https://access.redhat.com/errata/RHSA-2026:65851
- https://access.redhat.com/security/cve/CVE-2026-5946
- https://bugzilla.redhat.com/show_bug.cgi?id=2479771
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5946.json
JSON original (NVD)
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