CVE-2026-34478

N/A Unknown
Published: April 10, 2026 Modified: April 13, 2026
View on NVD

Description

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 log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes. Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly: * The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output. * The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping. Users of the SyslogAppender are not affected, as its configuration attributes were not modified. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
N/A / 10.0
EPSS (Exploit Probability)
0.1%
35th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)