CVE-2025-54812

Name	CVE-2025-54812
Description	Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur: * Log4cxx is configured to use HTMLLayout. * Logger name comes from an untrusted string * Logger with compromised name logs a message * User opens the generated HTML log file in their browser, leading to potential XSS Because logger names are generally constant strings, we assess the impact to users as LOW This issue affects Apache Log4cxx: before 1.5.0. Users are recommended to upgrade to version 1.5.0, which fixes the issue.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1111879

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
log4cxx (PTS)	bullseye	0.11.0-2	vulnerable
	bookworm	1.0.0-1	vulnerable
	forky, sid, trixie	1.4.0-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
log4cxx	source	(unstable)	(unfixed)			1111879

Notes

[trixie] - log4cxx <no-dsa> (Minor issue)
[bookworm] - log4cxx <no-dsa> (Minor issue)
https://logging.apache.org/security.html#CVE-2025-54812
https://github.com/apache/logging-log4cxx/pull/509
https://github.com/apache/logging-log4cxx/commit/1c599de956ae9eedd8b5e3f744bfb867c39e8bba (rel/v1.5.0, rv1.5.0-RC1)
https://github.com/apache/logging-log4cxx/pull/514
https://github.com/apache/logging-log4cxx/commit/36d829e9f6c3f9f4f9a42e22df326a9ed7b6e373 (rel/v1.5.0, rv1.5.0-RC1)