log4j vulnerabilities and fixes
Recent CVEs affecting log4j, with upgrade or downgrade steps. 1 tracked.
log4j has 1 tracked vulnerability, 0 critical. A fixed release or vendor patch exists for 1. Most recent: 2026-07-10. Highest priority: CVE-2026-49844 (score 43/100).
- CVE-2026-49844 MEDIUM 5.9 UPGRADE Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API
FAQ
How do I fix log4j vulnerabilities?
Open the CVE for your version, check the affected range, then follow the listed action: upgrade to the fixed release, or downgrade or mitigate if no fix exists yet. Commands for each OS are shown on every CVE page.
Is log4j being exploited right now?
None of the tracked log4j CVEs are on the CISA Known Exploited Vulnerabilities list at the moment. This is checked every 20 minutes.
Which log4j CVE should I patch first?
CVE-2026-49844 currently ranks highest (43/100): Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API.