Skip to main content
CVE-2025-54813VulnerabilityPublished Updated

CVE-2025-54813: Apache Log4cxx · Log Injection

Affects Apache Log4cxxSource CVE Database V5

0

Not known to be exploited · CVSS 6.3 Medium · fixed in 1.5.0 : update Apache Log4cxx when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score
6.3Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
1.3% chance of exploitation in 30 days – higher than 71% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.5.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 22 Aug 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Affected software

ProductAffectedFixed in
Apache Software Foundation Apache Log4cxxAffected
  • =0.11.0
Fixed in–

AI-suggested

The primary mitigation is to upgrade Apache Log4cxx to version 1.5.0 or later, where the JSONLayout escaping issue is fixed. Organizations should audit their environments to identify all instances of Log4cxx usage, especially those configured with JSONLayout, to ensure comprehensive patching. In parallel, review and enhance log ingestion and parsing pipelines to detect and handle malformed JSON logs gracefully, possibly by implementing validation and sanitization steps before log consumption. Employ monitoring to detect anomalies in log volume or format that may indicate exploitation attempts. Where immediate upgrade is not feasible, consider disabling JSONLayout or restricting log inputs to trusted sources to reduce exposure. Finally, update incident response playbooks to account for potential log integrity issues and ensure forensic readiness despite malformed logs.

Description

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.

References

Community reviews

Loading reviews…