CVE-2021-44228
Apache Log4j2 Remote Code Execution Vulnerability
IN CISA KEV
Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.
- Vendor
- Apache
- Product
- Log4j2
- CVSS 3.1
- 10 (critical), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CVSS 3.1
- 10 (critical), scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Published
- 2021-12-10
- NVD modified
- 2026-08-11
- NVD status
- Analyzed
CISA KEV
- Date added
- 2021-12-10
- Due date
- 2021-12-24
- Ransomware use
- Known
- 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.
EPSS
100% chance of exploitation in the next 30 days (percentile 99th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
ThreatWire coverage
References
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Broken Link, Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- packetstormsecurity.com (Third Party Advisory, VDB Entry)
- seclists.org (Mailing List, Third Party Advisory)
- seclists.org (Mailing List, Third Party Advisory)
- www.openwall.com (Mailing List, Mitigation, Third Party Advisory)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.