CVE-2025-54813: Apache Log4cxx · Log Injection
Affects Apache Log4cxxSource CVE Database V5
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
- 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:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software Foundation Apache Log4cxx | Affected
| 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.