CVE-2026-34478

ADVISORY - github

Summary

Apache Log4j Core's 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.

EPSS Score⁠: 0.00154 (0.356)

Common Weakness Enumeration (CWE)

ADVISORY - nist

CWE-117⁠

Improper Output Neutralization for Logs

CWE-684⁠

Incorrect Provision of Specified Functionality

ADVISORY - github

CWE-117⁠

Improper Output Neutralization for Logs

CWE-684⁠

Incorrect Provision of Specified Functionality

Impacted images

Advisories

NIST

CREATED

26 days ago

UPDATED

12 days ago

ADVISORY IDCVE-2026-34478⁠

EXPLOITABILITY SCORE

3.9

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)

CWE-117⁠CWE-684⁠

CVSS SCORE

6.9medium

GitHub

CREATED

26 days ago

UPDATED

23 days ago

ADVISORY IDGHSA-445c-vh5m-36rj⁠

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)

CWE-117⁠CWE-684⁠

CVSS SCORE

6.9medium

Debian

CREATED

24 days ago

UPDATED

8 days ago

ADVISORY IDCVE-2026-34478⁠

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

CVSS SCORE

N/Alow

Ubuntu

CREATED

23 days ago

UPDATED

10 days ago

ADVISORY IDCVE-2026-34478⁠

EXPLOITABILITY SCORE

3.9

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

CVSS SCORE

7.5medium

Chainguard

CREATED

11 hours ago

UPDATED

11 hours ago

ADVISORY ID

CGA-qw63-23v7-p6qc

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-26xc-8vr3-f3fg

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-2r54-3prx-9jh3

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-2vv6-9h26-723j

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-3gp9-x68q-ghv2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-4f39-xgm4-mh8x

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-4v9c-p23j-wfq8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-5cgq-gvph-69h2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-5f68-qp9h-jm4p

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-65j6-798c-5wvm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-682j-hww5-hg74

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-7p8v-pcx8-ppc9

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-7pp3-86vf-grj2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-8gwp-78hv-c82c

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-8r9m-7g9m-gjpp

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-93xh-cq2w-3c85

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-ccmj-w57x-22r8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-f49v-36vg-4g4f

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-f6xg-5rmv-6x82

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-g6j4-qp2v-938x

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

6 days ago

UPDATED

6 days ago

ADVISORY ID

MINI-g7fc-xgfq-2hv2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-h4gc-m9jp-2g7j

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-h85v-x485-4jv4

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-h8j5-hv3q-6vcr

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-hgf6-jcwj-x76v

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-hqf3-j5pq-fmvq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-j2p4-6hrx-qw3p

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-j595-j9g2-4r74

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-jwfq-prgm-w3v6

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-m9mv-3298-99fr

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

2 days ago

UPDATED

2 days ago

ADVISORY ID

MINI-mf3q-m5f3-p7wv

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-mf4v-fg2p-vqj6

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-p68x-2c4r-gfq6

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

11 days ago

UPDATED

11 days ago

ADVISORY ID

MINI-p75m-m7m8-j4rr

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-pcr2-qxm4-9q8w

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

7 days ago

UPDATED

7 days ago

ADVISORY ID

MINI-q3r8-fhw2-4xgh

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-rr49-9pp7-q4p8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-vcwv-r5j3-rq77

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-wqrq-hwv6-q872

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-wr3w-3xcq-v7m4

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-x672-vw6c-p392

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-xfw5-pvqf-x3q7

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-xg67-372m-9rmf

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-xh2m-5c7f-gfcq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-xmc7-753c-qvwh

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

7 days ago

UPDATED

7 days ago

ADVISORY ID

MINI-xpr8-mc5g-rqx8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-xwgh-6375-pvwh

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-xxcj-w7qr-ccqg

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY