CVE-2025-54812
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.
EPSS 1.16% · 65.0th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| apache | log4cxx | 0 |
| Apache Software Foundation | Apache Log4cxx | 0 |
Timeline
- Aug 22, 2025 PoC Published
- Aug 22, 2025 CVE Published
- Aug 22, 2025 PoC Published
- Aug 22, 2025 PoC Published
- Aug 23, 2025 EPSS Score
- Aug 31, 2025 EPSS Score
- Sep 8, 2025 EPSS Score
- Sep 16, 2025 EPSS Score
- Sep 24, 2025 EPSS Score
- Oct 3, 2025 EPSS Score
- Oct 11, 2025 EPSS Score
- Oct 19, 2025 EPSS Score
References
- https://logging.apache.org/security.html#CVE-2025-54812 vendor-advisory
- https://github.com/apache/logging-log4cxx/pull/509 patch
- https://github.com/apache/logging-log4cxx/pull/514 patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00002.html url
- http://www.openwall.com/lists/oss-security/2025/08/22/2 url
- https://nvd.nist.gov/vuln/detail/CVE-2025-54812 advisory