CVE-2026-5928
glibc: glibc: Information disclosure or denial of service via ungetwc function with specific wide character encodings
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 21, 2026
Updated · November 1, 2026
Description
A flaw was found in glibc (GNU C Library). When the ungetwc function is called on a file stream using wide characters with specific overlapping single-byte and multi-byte encodings, it may attempt to read data outside of its allocated buffer. This can lead to the unintentional disclosure of sensitive information from memory or cause the program to crash, resulting in a denial of service.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 5CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:H
CWE-125 · Out-of-bounds Read