CVE-2026-126831

Public on 2026-11-12
Modified on 2026-11-14
Description
A flaw was found in cpio. A local user can cause a Denial of Service (DoS) by triggering a stack-based buffer overflow when creating archives in tar or ustar formats. When archiving files owned by users or groups with names exceeding 32 characters, cpio copies these names into fixed-size memory without verifying their length. This unbounded copy corrupts stack memory and causes the application to crash.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core cpio Pending Fix
Amazon Linux 2023 cpio Pending Fix
Amazon Linux 2027 Preview cpio Pending Fix
Amazon Linux 2 - Core python-cpio Not Affected
Amazon Linux 2023 python-cpio Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H