CVE-2025-54812 LOW

CVE-2025-54812: Apache Log4cxx: Improper HTML escaping in HTMLLayout

Vendor Apache Software Foundation
Product Apache Log4cxx
Weakness CWE-117
Published August 22, 2025
Last update November 4, 2025

CVSS base score

2.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

What the vulnerability does

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.

Key dates

Disclosure timeline

August 22, 2025 CVE published
November 4, 2025 Record updated