CVE-2026-12505: Red Hat Enterprise Linux 10

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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 Red Hat Enterprise Linux 10: before 0:7.6-1.el10_2 (fixed in 0:7.6-1.el10_2)
• Red Hat Red Hat Enterprise Linux 6
• Red Hat Red Hat Enterprise Linux 7
• Red Hat Red Hat Enterprise Linux 8: before 0:7.0-5.el8_10 (fixed in 0:7.0-5.el8_10)
• Red Hat Red Hat Enterprise Linux 9: before 0:7.6-2.el9_8 (fixed in 0:7.6-2.el9_8)
• Red Hat Red Hat Openshift Container Platform 4
• Red Hat Red Hat Openshift Container Platform 4.22: before 4.22.9.8.202607220526-0 (fixed in 4.22.9.8.202607220526-0)

Published 2026-06-18. Last modified 2026-08-31.