Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Affects Red HatSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 6.1 Medium.
Data as of 2 Nov 2026, 06:31 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
AI-suggested
To mitigate this vulnerability, remove the 'user' option from any loop mounts in the /etc/fstab file or ensure that the source path points to a root-owned directory where unprivileged users do not have write permissions. The Red Hat advisory does not indicate that a patch is currently available for this issue in the Hardened Images RPMs. Therefore, applying these configuration changes is the recommended mitigation until an official fix is released.
Description
A moderate severity vulnerability (CVE-2026-27456) exists in util-linux's mount program related to a Time-of-Check-Time-of-Use (TOCTOU) race condition when mounting loop devices with user and loop options in /etc/fstab. This flaw allows a local unprivileged user to gain full read access to root-owned files or block devices containing valid filesystems by exploiting a brief window where the mount program checks file paths with user permissions but opens them with root privileges. There is no memory corruption or code execution involved. The vulnerability is only exploitable if an /etc/fstab entry uses user,loop options and the source path is writable by the attacker. The Red Hat Hardened Images RPMs update advisory references this and other CVEs but does not list specific fixes for this issue. Mitigation involves removing the 'user' option from loop mounts or ensuring source paths are root-owned and not writable by unprivileged users.
References
- access.redhat.com/errata/RHSA-2026:7180 (opens in a new tab)
- images.redhat.com (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-27456 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- access.redhat.com/security/cve/CVE-2025-14104 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-3184 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_7180.json (opens in a new tab)