CVE-2021-44228Actively exploitedAdded to KEV 2021-12-10Known ransomware campaign use

Apache Log4j2 Remote Code Execution Vulnerability

Apache, Log4j2

Description

Apache Log4j2 contains a vulnerability where JNDI features do not protect against attacker-controlled JNDI-related endpoints, allowing for remote code execution.

CVSS severity for this advisory hasn't been enriched from NVD yet, check back shortly.

EPSS, exploit probability

Critical

100.0%

estimated chance of real-world exploitation in the next 30 days, higher than 100.0% of every CVE FIRST.org scores

Refreshed 10/28/2026, via FIRST.org's EPSS model, not CVSS, this measures likelihood of exploitation, not how severe it would be.

Required action

For all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available.

CISA-recommended due date: 2021-12-24

CWE-20 CWE-400 CWE-502

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