Vulnerability in Apache Log4cxx

CVE-2025-54813

Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using JSONLayout, not all payload bytes are properly escaped. If an attacker-supplied message contains certain non-printable characters, these will be passed along in the message and written out as part of the JSON message. This may prevent applications that consume these logs from correctly interpreting the information within them. This issue affects Apache Log4cxx: before 1.5.0. Users are recommended to upgrade to version 1.5.0, which fixes the issue.

EPSS: 0.013 (67.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-54813?
CVE-2025-54813 is a high-severity vulnerability in Apache Log4cxx, classified under Improper Output Neutralization for Logs. CVSS score: 7.5/10. Published 2025-08-22.
How severe is CVE-2025-54813?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-54813 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.