CVE-2021-3493

HighCVSS 7.8/10Known exploited (CISA KEV)Last modified Jun 17, 2026

Description

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

Metrics

CVSS 3.1 7.8/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-270CWE-863

Affected software

No affected versions have been published.

Timeline

Published
Apr 17, 2021
Last modified
Jun 17, 2026
Added to CISA KEV
Oct 20, 2022
NVD status
Analyzed

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CVE-2021-3493: High severity, CVSS 7.8 | Vulnix