CVE-2023-26464

HIGH EXPLOITED

Apache Log4j < 2.0 - Denial of Service via Chainsaw or SocketAppender Deserialization

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2023-26464 has been observed exploited in the wild (reported by VulnCheck KEV).

Description

** 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.

References (2)

Core 2

Scores

CVSS v3 7.5
EPSS 0.0013
EPSS Percentile 31.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

VulnCheck KEV 2025-12-08
CWE
CWE-502
Status published
Products (3)
apache/log4j 1.0.4 - 2.0
log4j/log4j 1.0.4 - 2.0Maven
org.apache.logging.log4j/log4j-core 1.0.4 - 2.0Maven
Published Mar 10, 2023
Tracked Since Feb 18, 2026