What it is
The overlayfs stacking file system in Linux kernel does not properly validate the application of file capabilities against user namespaces, which could lead to privilege escalation.
What to do
Apply updates per vendor instructions.
Vendor notices and references
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc39
- nvd.nist.gov/vuln/detail/CVE-2021-3493
Description and required action as published by CISA. Full record at NVD.
Other Linux entries on the list
- Kernel Linux Kernel Missing Initialization of a Variable Vulnerability CVE-2026-46300 · Oct 28, 2026
- Kernel Linux Kernel Out-of-Bounds Write Vulnerability CVE-2026-53266 · Sep 18, 2026
- Kernel Linux Kernel Race Condition Vulnerability CVE-2025-39964 · Sep 18, 2026
- Kernel Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability CVE-2025-39682 · Sep 18, 2026
- Kernel Linux Kernel Unspecified Vulnerability CVE-2026-53362 · Aug 27, 2026
- Kernel Linux Kernel Out-of-Bounds Write Vulnerability CVE-2022-0995 · Aug 26, 2026