CVE-2026-12505
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 4
- Fecha de la puntuación: 5/10/2026
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
T1068Exploitation for Privilege Escalationprivilege escalation95 % - Impacto secundario
T1059Command and Scripting Interpreterexecution85 %
Vulnerabilidad local (AV:L, PR:L) que permite escalada a root mediante manipulación de namespaces y módulos NSS. El atacante ejecuta comandos arbitrarios con privilegios de administrador.
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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-250
- CWE-250
Referencias
- https://access.redhat.com/errata/RHSA-2026:32990
- https://access.redhat.com/errata/RHSA-2026:39575
- https://access.redhat.com/errata/RHSA-2026:39576
- https://access.redhat.com/errata/RHSA-2026:44232
- https://access.redhat.com/security/cve/CVE-2026-12505
- https://bugzilla.redhat.com/show_bug.cgi?id=2489805
- https://git.samba.org/?p=cifs-utils.git;a=commit;h=972c5b5ff95e3e812bc8daa72d0383654ab0dba7
- https://access.redhat.com/errata/RHSA-2026:32990
- https://access.redhat.com/errata/RHSA-2026:39575
- https://access.redhat.com/errata/RHSA-2026:39576
- https://access.redhat.com/errata/RHSA-2026:44232
- https://access.redhat.com/security/cve/CVE-2026-12505
- https://bugzilla.redhat.com/show_bug.cgi?id=2489805
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12505.json
JSON original (NVD)
Mostrar
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