Improper Check or Handling of Exceptional Conditions in Linux kernel - CVE-2026-53174

Vulnerability identifier: #VU135618

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53174

CWE-ID: CWE-703

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper error handling in ovl_iterate_merged() in fs/overlayfs/readdir.c when processing readdir operations on overlay-on-overlay directories. A local user can trigger nested directory iteration to cause a denial of service.

The issue is reachable through overlay-on-overlay readdir via getdents64.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/1711b6ed6953cee5940ca4c3a6e77f1b3798cee2
• https://git.kernel.org/stable/c/e7051909a01bfb883bfa78b27514854068ac4b85

• Improper Check or Handling of Exceptional Conditions in Linux kernel overlayfs
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia