Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
History

Thu, 23 Apr 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu glibc
Weaknesses CWE-787
CPEs cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
Vendors & Products Gnu
Gnu glibc

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-131
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 20 Apr 2026 23:15:00 +0000

Type Values Removed Values Added
First Time appeared The Gnu C Library
The Gnu C Library glibc
Vendors & Products The Gnu C Library
The Gnu C Library glibc

Mon, 20 Apr 2026 21:00:00 +0000

Type Values Removed Values Added
Description Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
Title scanf %mc off-by-one heap buffer overflow
Weaknesses CWE-122
References

cve-icon MITRE

Status: PUBLISHED

Assigner: glibc

Published: 2026-04-20T20:55:41.170Z

Updated: 2026-04-21T19:49:53.221Z

Reserved: 2026-04-02T21:47:21.403Z

Link: CVE-2026-5450

cve-icon Vulnrichment

Updated: 2026-04-21T16:04:17.997Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-20T21:16:36.850

Modified: 2026-04-23T15:33:34.277

Link: CVE-2026-5450

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-20T20:55:41Z

Links: CVE-2026-5450 - Bugzilla