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CVE-2021-3493
CWE-270
Critical
97.3
RPSRPS range: 0–105; KEV-listed vulnerabilities can receive an exploitation amplifier.
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.
Source: NVD
Signals
- CVSS
- 8.8
- High · v3.1
- EPSS
- 49.16%
- Probability of exploitation in the next 30 days (FIRST)
- CISA KEV
- In CISA KEV since Oct 2022
- Fix commit
- No known fix commit
- Sources: MoreFixes, FreshFixes
- Weakness
- CWE-270
- CWE-270, CWE-863
- Published
- 17 Apr 2021
- Last modified 28 Oct 2025
How to read these signals: RPS · EPSS · CISA KEV · Data sources
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Data as of 7 Oct 2026, 05:16 UK time