CISA KEV entry
CVE-2021-45046Apache Log4j2 Deserialization of Untrusted Data Vulnerability
Apache Log4j2. Added to the CISA Known Exploited Vulnerabilities catalogue on 1 May 2023.
Data status: a source is stale
Last synced CISA catalogue version 2026.11.04 (released 4 November 2026) 1,768 entries Updated manually
- Date added
- 2023-05-01
- Federal due date
- 2023-05-22 21 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Known
- Forensic triage (BOD 26-04)
- No
- CVSS
- 9.0 Critical CVSS 3.1, scored by nvd@nist.gov
- EPSS
- 99.97% percentile 99.9, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable no, technical impact total
- NVD status
- Analyzed published 2021-12-14, 503 days before the KEV listing
BOD 26-04 remediation window
With CISA's SSVC answers for this CVE (automatable: no, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 3) and 14 days on an asset that is not publicly exposed (row 11) S06. The catalogue due date, 21 days after the date added, was set before BOD 26-04 took effect on 10 June 2026 S06. The directive binds US federal civilian executive branch agencies only.
What CISA says
Short description
Apache Log4j2 contains a deserialization of untrusted data vulnerability due to the incomplete fix of CVE-2021-44228, where the Thread Context Lookup Pattern is vulnerable to remote code execution in certain non-default configurations.
Required action
Apply updates per vendor instructions.
Notes
https://logging.apache.org/log4j/2.x/security.html; https://nvd.nist.gov/vuln/detail/CVE-2021-45046
CWE in the catalogue
CWE-917
Official links
- CISA KEV catalogue entry cisa.gov
- NVD record nvd.nist.gov
Vendor advisory and patch links
References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.
- https://logging.apache.org/log4j/2.x/security.html Mitigation, Release Notes, Vendor Advisory
- https://www.oracle.com/security-alerts/cpujan2022.html Patch, Third Party Advisory
Links in CISA's notes
NVD details
- CWE (NVD)
- CWE-917 by security@apache.org
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H- CVSS versions in NVD
- V2, V31
- Last modified in NVD
- 2026-06-17T04:13:05.570
Where each value comes from
| Field | Source | Fetched, UTC | State |
|---|---|---|---|
| Catalogue fields | CISA KEV JSON, version 2026.11.04 | 2026-11-05 11:38 | current |
| NVD published, status, CVSS, CWE, vendor links | NVD CVE API 2.0; CVSS: NVD (nvd@nist.gov) | 2026-11-03 12:37 | current at 2026-11-05 11:38 |
| EPSS | FIRST EPSS API, scores of 2026-11-04 | 2026-11-05 11:38 | current |
| CISA SSVC | CISA ADP (via NVD), record of 2025-02-04 | 2026-11-03 12:37 | current |
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