CVE-2023-26464: Log4j core Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-vp98-w2p3-mv35
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CVSS 7.5
CWE-502 CWE-400
Published
Advisory Summary

CVE-2023-26464 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Log4j core libraries in the Maven ecosystem. The issue involves apache log4j 1.x (eol) allows denial of service (dos). Remediation is available by upgrading affected packages to version 2.0.

CVE-2023-26464 at a Glance

CVE Identifier CVE-2023-26464
GHSA Identifier GHSA-vp98-w2p3-mv35
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Log4j core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2023-26464

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.

org.apache.logging.log4j:log4j-core fixed: 2.0 
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.0</version>
</dependency>
log4j:log4j fixed: 2.0 
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>2.0</version>
</dependency>
Verify Direct and Transitive Dependencies

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-2023-26464, 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 2.0), 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-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. 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

** 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 logging entry involving a specially-crafted (ie deeply nested) hashmap or hashtable (depending on which logging component is in use) to be processed could exhaust the available memory in the virtual machine and achieve Denial of Service when the object is deserialized. This issue affects Apache Log4j before 2. Affected users are recommended to update to Log4j 2.x. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

CVE-2023-26464 Affected Log4j core Versions

2 component(s)
Fixed Versions:
2.0
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.logging.log4j:log4j-core
maven/org.apache.logging.log4j/log4j-core
Maven
≥ 1.0.4
< 2.0
2.0
log4j:log4j
maven/log4j/log4j
Maven
≥ 1.0.4
< 2.0
2.0

References

NVD — CVE-2023-26464 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-26464
Log4j core Source Repository REPOSITORY
https://github.com/apache/logging-log4j2
lists.apache.org/thread/wkx6grrcjkh8... WEB
https://lists.apache.org/thread/wkx6grrcjkh86crr49p4blc1v1nflj3t
Log4j core Security Information SECURITY
https://security.netapp.com/advisory/ntap-20230505-0008

Frequently Asked Questions

What is CVE-2023-26464?
CVE-2023-26464 is a security vulnerability in Log4j core involving Apache Log4j 1.x (EOL) allows Denial of Service (DoS) under CWE-502: Deserialization of Untrusted Data.
Which Log4j core versions are affected?
Affected versions include releases prior to 2.0 across affected packages: org.apache.logging.log4j:log4j-core, log4j:log4j.
What version fixes CVE-2023-26464?
Upgrading to 2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is log4j-core affected?
Yes, org.apache.logging.log4j:log4j-core is affected in releases prior to 2.0. Upgrade your dependency to 2.0 or later.
Is log4j affected?
Yes, log4j:log4j is affected in releases prior to 2.0. Upgrade your dependency to 2.0 or later.
What is the CVSS score of CVE-2023-26464?
CVE-2023-26464 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2023-26464?
CVE-2023-26464 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Maven dependencies for CVE-2023-26464?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.logging.log4j'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vp98-w2p3-mv35",
  "modified" : "2025-09-02T22:25:25Z",
  "published" : "2023-03-10T15:30:43Z",
  "aliases" : [ "CVE-2023-26464" ],
  "summary" : "Apache Log4j 1.x (EOL) allows Denial of Service (DoS)",
  "details" : "** 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 logging entry involving a specially-crafted (ie deeply nested) hashmap or hashtable (depending on which logging component is in use) to be processed could exhaust the available memory in the virtual machine and achieve Denial of Service when the object is deserialized. This issue affects Apache Log4j before 2. Affected users are recommended to update to Log4j 2.x. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.logging.log4j:log4j-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.4"
      }, {
        "fixed" : "2.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "log4j:log4j"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.4"
      }, {
        "fixed" : "2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-26464"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/logging-log4j2"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread/wkx6grrcjkh86crr49p4blc1v1nflj3t"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20230505-0008"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-502" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-10T23:48:32Z",
    "nvd_published_at" : "2023-03-10T14:15:00Z"
  }
}