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.

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Fixes

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History

Fri, 13 Nov 2026 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Red Hat
Red Hat enterprise Linux
Redhat hardened Images
Vendors & Products Red Hat
Red Hat enterprise Linux
Redhat hardened Images

Fri, 13 Nov 2026 00:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 12 Nov 2026 17:45:00 +0000

Type Values Removed Values Added
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.
Title Cpio: cpio: stack-based buffer overflow in write_out_tar_header() with long usernames/groupnames
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat rhel Els
Weaknesses CWE-121
CPEs cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat rhel Els
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-11-12T17:27:16.588Z

Reserved: 2026-11-11T21:04:08.843Z

Link: CVE-2026-126831

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-12T18:17:28.583

Modified: 2026-11-12T18:17:28.890

Link: CVE-2026-126831

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-11-07T00:00:00Z

Links: CVE-2026-126831 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-11-13T02:30:04Z

Weaknesses