CVE-2026-12505

Cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall

CVSS 3.1 7.8 HIGHCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-12505

Published

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.

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Affected versions, risk and source history

Exploitation and risk

Source status

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Risk history

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Advisory history

3 saved versions

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4 Nov 2026 23:54:02 UTC