Apache Log4j
20 CVEs affecting Apache Log4j. Latest disclosed: 2026-07-10. Critical: 6, High: 8.
| CVE | Severity | Score | Published | Summary |
|---|---|---|---|---|
CVE-2021-44228 | Critical | 10.0 | 2021-12-10 | 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 parameter… |
CVE-2022-23305 | Critical | 9.8 | 2022-01-18 | By design, the JDBCAppender in Log4j 1.2.x accepts an SQL statement as a configuration parameter where the values to be inserted are converters from PatternLay… |
CVE-2020-9493 | Critical | 9.8 | 2021-06-16 | A deserialization flaw was found in Apache Chainsaw versions prior to 2.1.0 which could lead to malicious code execution. |
CVE-2019-17571 | Critical | 9.8 | 2019-12-20 | Included in Log4j 1.2 is a SocketServer class that is vulnerable to deserialization of untrusted data which can be exploited to remotely execute arbitrary code… |
CVE-2017-5645 | Critical | 9.8 | 2017-04-17 | In Apache Log4j 2.x before 2.8.2, when using the TCP socket server or UDP socket server to receive serialized log events from another application, a specially… |
CVE-2021-45046 | Critical | 9.0 | 2021-12-14 | It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers wi… |
CVE-2022-23307 | High | 8.8 | 2022-01-18 | CVE-2020-9493 identified a deserialization issue that was present in Apache Chainsaw. Prior to Chainsaw V2.0 Chainsaw was a component of Apache Log4j 1.2.x whe… |
CVE-2022-23302 | High | 8.8 | 2022-01-18 | JMSSink in all versions of Log4j 1.x is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration or if the… |
CVE-2026-34481 | High | 7.5 | 2026-04-10 | Apache Log4j's JsonTemplateLayout https://logging.apache.org/log4j/2.x/manual/json-template-layout.html , in versions up to and including 2.25.3, produces inv… |
CVE-2026-34480 | High | 7.5 | 2026-04-10 | Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize c… |
CVE-2026-34479 | High | 7.5 | 2026-04-10 | The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Con… |
CVE-2026-34478 | High | 7.5 | 2026-04-10 | Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to… |
CVE-2023-26464 | High | 7.5 | 2023-03-10 | ** UNSUPPORTED WHEN ASSIGNED ** When using the Chainsaw or SocketAppender components with Log4j 1.x on JRE less than 1.7, an attacker that manages to cause a… |
CVE-2021-4104 | High | 7.5 | 2021-12-14 | JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration. The attacker can pro… |
CVE-2021-44832 | Medium | 6.6 | 2021-12-28 | Apache Log4j2 versions 2.0-beta7 through 2.17.0 (excluding security fix releases 2.3.2 and 2.12.4) are vulnerable to a remote code execution (RCE) attack when… |
CVE-2026-49844 | Medium | 5.9 | 2026-07-10 | Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This iss… |
CVE-2026-34477 | Medium | 5.9 | 2026-04-10 | The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via t… |
CVE-2021-45105 | Medium | 5.9 | 2021-12-18 | Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This a… |
CVE-2025-68161 | Medium | 4.8 | 2025-12-18 | The Socket Appender in Apache Log4j Core versions 2.0-beta9 through 2.25.2 does not perform TLS hostname verification of the peer certificate, even when the v… |
CVE-2020-9488 | Low | 3.7 | 2020-04-27 | Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-mid… |