Vulnerabilities in pkg:maven/org.apache.logging.log4j/log4j-core
PACKAGECVE-2021-45046 is a CRITICAL (CVSS 9.0) incomplete fix for apache log4j vulnerability (CWE-917: Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')) affecting Log4j core libraries in the Maven ecosystem. The issue involves incomplete fix for apache log4j vulnerability. Remediation is available by upgrading affected packages to version 2.16.0, 2.12.2, 1.9.2, 1.10.8, 1.11.11, 2.0.12, 2.3.1.
pkg:maven/org.apache.logging.log4j/log4j-core
Vulnerability advisories affecting package pkg:maven/org.apache.logging.log4j/log4j-core. Select an advisory below to view technical details or fixes.
| Advisory ID | CVE / NVD | Severity | Summary |
|---|---|---|---|
| GHSA-7rjr-3q55-vv33 | CVE-2021-45046 | CRITICAL | Incomplete fix for Apache Log4j vulnerability |
| GHSA-8489-44mv-ggj8 | CVE-2021-44832 | MODERATE | Improper Input Validation and Injection in Apache Log4j2 |
| GHSA-vwqq-5vrc-xw9h | CVE-2020-9488 | LOW | Improper validation of certificate with host mismatch in Apache Log4j SMTP appender |
| GHSA-p6xc-xr62-6r2g | CVE-2021-45105 | HIGH | Apache Log4j2 vulnerable to Improper Input Validation and Uncontrolled Recursion |
| GHSA-445c-vh5m-36rj | CVE-2026-34478 | MODERATE | Apache Log4j Core: log injection in `Rfc5424Layout` due to silent configuration incompatibility |
| GHSA-6hg6-v5c8-fphq | CVE-2026-34477 | MODERATE | Apache Log4j Core: `verifyHostName` attribute silently ignored in TLS configuration |
| GHSA-3pxv-7cmr-fjr4 | CVE-2026-34480 | MODERATE | Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters |
| GHSA-vc5p-v9hr-52mj | CVE-2025-68161 | MODERATE | Apache Log4j does not verify the TLS hostname in its Socket Appender |
| GHSA-jfh8-c2jp-5v3q | CVE-2021-44228 | CRITICAL | Remote code injection in Log4j |
| GHSA-vp98-w2p3-mv35 | CVE-2023-26464 | HIGH | Apache Log4j 1.x (EOL) allows Denial of Service (DoS) |
| GHSA-fxph-q3j8-mv87 | CVE-2017-5645 | CRITICAL | Deserialization of Untrusted Data in Log4j |
CVE-2021-45046 at a Glance
Security Impact
CVSS: 9.0
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H).
How to Fix CVE-2021-45046
To remediate this vulnerability, upgrade all affected Log4j core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.16.0</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.12.2</version>
</dependency>
<dependency>
<groupId>org.ops4j.pax.logging</groupId>
<artifactId>pax-logging-log4j2</artifactId>
<version>1.9.2</version>
</dependency>
<dependency>
<groupId>org.ops4j.pax.logging</groupId>
<artifactId>pax-logging-log4j2</artifactId>
<version>1.10.8</version>
</dependency>
<dependency>
<groupId>org.ops4j.pax.logging</groupId>
<artifactId>pax-logging-log4j2</artifactId>
<version>1.11.11</version>
</dependency>
<dependency>
<groupId>org.ops4j.pax.logging</groupId>
<artifactId>pax-logging-log4j2</artifactId>
<version>2.0.12</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.3.1</version>
</dependency>
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.apache.logging.log4j
How to Check if You Are Affected
To determine whether your Java application is affected by CVE-2021-45046, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.apache.logging.log4j
Analyze the terminal output to locate any version of Log4j core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.16.0), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.apache.logging.log4j command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-917: Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection'), where the product constructs all or part of an expression language (el) statement in a framework such as a java server page (jsp) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended el statement before it is executed. In Log4j core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-45046 Affected Log4j core Versions
7 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.apache.logging.log4j:log4j-core
|
Maven |
≥ 2.13.0
< 2.16.0
|
2.16.0
|
|
org.apache.logging.log4j:log4j-core
|
Maven |
≥ 2.4.0
< 2.12.2
|
2.12.2
|
|
org.ops4j.pax.logging:pax-logging-log4j2
|
Maven |
≥ 1.8.0
< 1.9.2
|
1.9.2
|
|
org.ops4j.pax.logging:pax-logging-log4j2
|
Maven |
≥ 1.10.0
< 1.10.8
|
1.10.8
|
|
org.ops4j.pax.logging:pax-logging-log4j2
|
Maven |
≥ 1.11.0
< 1.11.11
|
1.11.11
|
|
org.ops4j.pax.logging:pax-logging-log4j2
|
Maven |
≥ 2.0.0
< 2.0.12
|
2.0.12
|
|
org.apache.logging.log4j:log4j-core
|
Maven |
< 2.3.1
|
2.3.1
|
References
Frequently Asked Questions
What is CVE-2021-45046?
Which Log4j core versions are affected?
What version fixes CVE-2021-45046?
Is log4j-core affected?
Is pax-logging-log4j2 affected?
What is the CVSS score of CVE-2021-45046?
What CWE is associated with CVE-2021-45046?
How can I check Maven dependencies for CVE-2021-45046?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-7rjr-3q55-vv33",
"modified" : "2026-10-02T20:21:52Z",
"published" : "2021-12-14T18:01:28Z",
"aliases" : [ "CVE-2021-45046" ],
"summary" : "Incomplete fix for Apache Log4j vulnerability",
"details" : "# Impact\n\nThe fix to address [CVE-2021-44228](https://nvd.nist.gov/vuln/detail/CVE-2021-44228) in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allow attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in a remote code execution (RCE) attack. \n\n## Affected packages\nOnly the `org.apache.logging.log4j:log4j-core` package is directly affected by this vulnerability. The `org.apache.logging.log4j:log4j-api` should be kept at the same version as the `org.apache.logging.log4j:log4j-core` package to ensure compatability if in use.\n\n# Mitigation\n\nLog4j 2.16.0 fixes this issue by removing support for message lookup patterns and disabling JNDI functionality by default. This issue can be mitigated in prior releases (< 2.16.0) by removing the JndiLookup class from the classpath (example: zip -q -d log4j-core-*.jar org/apache/logging/log4j/core/lookup/JndiLookup.class).\n\nLog4j 2.15.0 restricts JNDI LDAP lookups to localhost by default. Note that previous mitigations involving configuration such as to set the system property `log4j2.formatMsgNoLookups` to `true` do NOT mitigate this specific vulnerability.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.apache.logging.log4j:log4j-core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.13.0"
}, {
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} ]
} ]
}, {
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"name" : "org.apache.logging.log4j:log4j-core"
},
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"events" : [ {
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}, {
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} ]
} ]
}, {
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"name" : "org.ops4j.pax.logging:pax-logging-log4j2"
},
"ranges" : [ {
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"events" : [ {
"introduced" : "1.8.0"
}, {
"fixed" : "1.9.2"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.ops4j.pax.logging:pax-logging-log4j2"
},
"ranges" : [ {
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}, {
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} ]
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}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.ops4j.pax.logging:pax-logging-log4j2"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.11.0"
}, {
"fixed" : "1.11.11"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.ops4j.pax.logging:pax-logging-log4j2"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.0.0"
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} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.apache.logging.log4j:log4j-core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "2.3.1"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-45046"
}, {
"type" : "WEB",
"url" : "https://www.oracle.com/security-alerts/cpujul2022.html"
}, {
"type" : "WEB",
"url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
}, {
"type" : "WEB",
"url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
}, {
"type" : "WEB",
"url" : "https://www.oracle.com/security-alerts/alert-cve-2021-44228.html"
}, {
"type" : "WEB",
"url" : "https://www.openwall.com/lists/oss-security/2021/12/18/1"
}, {
"type" : "WEB",
"url" : "https://www.openwall.com/lists/oss-security/2021/12/15/3"
}, {
"type" : "WEB",
"url" : "https://www.openwall.com/lists/oss-security/2021/12/14/4"
}, {
"type" : "WEB",
"url" : "https://www.kb.cert.org/vuls/id/930724"
}, {
"type" : "WEB",
"url" : "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html"
}, {
"type" : "WEB",
"url" : "https://www.debian.org/security/2021/dsa-5022"
}, {
"type" : "WEB",
"url" : "https://www.cve.org/CVERecord?id=CVE-2021-44228"
}, {
"type" : "WEB",
"url" : "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-45046"
}, {
"type" : "WEB",
"url" : "https://security.gentoo.org/glsa/202310-16"
}, {
"type" : "WEB",
"url" : "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd"
}, {
"type" : "WEB",
"url" : "https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032"
}, {
"type" : "WEB",
"url" : "https://logging.apache.org/security.html#CVE-2021-45046"
}, {
"type" : "WEB",
"url" : "https://logging.apache.org/log4j/2.x/security.html"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SIG7FZULMNK2XF6FZRU4VWYDQXNMUGAJ"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EOKPQGV24RRBBI4TBZUDQMM4MEH7MXCY"
}, {
"type" : "WEB",
"url" : "https://github.com/apache/logging-log4j2/compare/rel/2.3...rel/2.3.1"
}, {
"type" : "WEB",
"url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf"
}, {
"type" : "WEB",
"url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf"
}, {
"type" : "WEB",
"url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf"
}, {
"type" : "WEB",
"url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-502", "CWE-917" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2021-12-14T17:55:00Z",
"nvd_published_at" : "2021-12-14T19:15:00Z"
}
}