ACTIVELY EXPLOITED
CVE-2021-45046: Apache Log4j2 Deserialization of Untrusted Data Vulnerability
| Vendor | Apache |
|---|---|
| Product | Log4j2 |
| Actively exploited | Yes |
| Added to CISA KEV | 1 May 2023 |
| CISA federal deadline | 22 May 2023 |
| Ransomware use | Known |
| Weakness (CWE) | CWE-917 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
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.
SOURCES
Other Apache flaws
- CVE-2016-3081: Apache Struts Command Injection Vulnerability
- CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability
- CVE-2026-34197: Apache ActiveMQ Improper Input Validation Vulnerability
- CVE-2024-38475: Apache HTTP Server Improper Escaping of Output Vulnerability
- CVE-2025-24813: Apache Tomcat Path Equivalence Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.