CVE-2026-12505: Cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-18 · updated 2026-10-14
Weakness: CWE-250

Description

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.

Affected products

Red Hat OpenShift Container Platform 4.18: all versions
Red Hat Enterprise Linux 10: all versions — fixed in 0:7.6-1.el10_2
Red Hat Enterprise Linux 8: all versions — fixed in 0:7.0-5.el8_10
Red Hat Enterprise Linux 9: all versions — fixed in 0:7.6-2.el9_8
Red Hat OpenShift Container Platform 4.22: all versions — fixed in 4.22.9.8.202607220526-0

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:7.6-1.el10_2; Red Hat Enterprise Linux 8 0:7.0-5.el8_10; Red Hat Enterprise Linux 9 0:7.6-2.el9_8; Red Hat OpenShift Container Platform 4.22 4.22.9.8.202607220526-0. Check the vendor advisory for mitigations.

References

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