CVE-2023-4255: Fedoraproject Extra Packages For Enterprise Linux

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.

Affected products

• Fedoraproject Extra Packages For Enterprise Linux: version 8.0 only
• Fedoraproject Fedora: version 39 only
• Tats w3m: version 0.5.3+git20230121-1 only; version 0.5.3+git20230121-2 only; version 0.5.3+git20230129 only

Published 2023-12-21. Last modified 2026-06-17.