CVE-2026-34480

ADVISORY - github

Summary

Apache Log4j Core's XmlLayout, in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification, producing invalid XML output whenever a log message or MDC value contains such characters.

The impact depends on the StAX implementation in use:

JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.
Alternative StAX implementations (e.g., Woodstox, a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger.

Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.

EPSS Score⁠: 0.00153 (0.355)

Common Weakness Enumeration (CWE)

ADVISORY - nist

CWE-116⁠

Improper Encoding or Escaping of Output

ADVISORY - github

CWE-116⁠

Improper Encoding or Escaping of Output

Impacted images

Advisories

NIST

CREATED

26 days ago

UPDATED

12 days ago

ADVISORY IDCVE-2026-34480⁠

EXPLOITABILITY SCORE

3.9

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)

CWE-116⁠

CVSS SCORE

6.9medium

GitHub

CREATED

26 days ago

UPDATED

23 days ago

ADVISORY IDGHSA-3pxv-7cmr-fjr4⁠

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)

CWE-116⁠

CVSS SCORE

6.9medium

Debian

CREATED

24 days ago

UPDATED

8 days ago

ADVISORY IDCVE-2026-34480⁠

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

Ubuntu

CREATED

23 days ago

UPDATED

10 days ago

ADVISORY IDCVE-2026-34480⁠

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-wqhw-vh22-jwgm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-2589-36pf-gwmm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-268h-qw5h-mhqh

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-28gp-6rr2-24m7

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-2hqc-qjfr-jrgp

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-32m4-cjmq-q78f

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-32p2-96qj-fxqx

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-3923-684f-cqp2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

7 days ago

UPDATED

7 days ago

ADVISORY ID

MINI-3hhg-jppj-8mp2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-43mr-cfvq-464g

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-4hrw-4g69-8vg5

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-4mv8-g575-pg3p

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-4mx3-p93p-fc4f

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-4rh7-cc9x-jmmf

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-568v-9j7v-9h5q

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-5c62-vfhc-7v5j

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-5q6x-7jgg-98j3

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-6jc4-j29r-v84p

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-6p37-5j3c-w2vr

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-7ghf-qjxg-p3vc

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-7hvg-j6jr-4fgj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-7j2p-vcg4-8f24

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-87xc-xjx6-9864

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-8fhg-pv9x-jh34

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-8ppp-gvqm-22wq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-8q2w-7frq-hqjv

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-95xm-p5qh-x6fq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-9pwq-cr7m-672g

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-9rq7-4gqc-qhp8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-9rr6-prjm-f28w

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-c2xm-w5v6-rgcj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-c3vg-wf42-95jf

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-c8x8-8cmw-p5c5

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-cqv8-m92q-9f3m

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-cw4r-7xq7-99v9

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-ffc9-cr6w-jr28

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-g9pp-75j4-qpjm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-h38g-4h2f-qqcj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-h94q-r36w-x3qp

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-hqqc-xxr4-mwhj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-j37p-c735-25hq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

6 days ago

UPDATED

6 days ago

ADVISORY ID

MINI-j66x-9cqx-hmj5

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-m3hm-68vp-7rqj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

22 days ago

UPDATED

22 days ago

ADVISORY ID

MINI-m88j-mrfv-fj6j

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-mfhj-v9fx-vf33

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-p934-hhvm-f2hq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-pc6f-986x-g2q5

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

7 days ago

UPDATED

7 days ago

ADVISORY ID

MINI-pjf5-8gxj-fvcq

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

2 days ago

UPDATED

2 days ago

ADVISORY ID

MINI-pqc5-hpq2-x6wg

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

11 days ago

UPDATED

11 days ago

ADVISORY ID

MINI-q44j-gchf-6qj2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-q7c2-4wj7-g473

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-qm8c-rjf2-wwc3

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-qwpw-vcqc-p2j2

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-rf2r-32gg-78h8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

17 days ago

UPDATED

17 days ago

ADVISORY ID

MINI-rq57-m8w3-x28p

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

9 days ago

UPDATED

9 days ago

ADVISORY ID

MINI-rxqp-gq37-vwff

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-v4c6-mx66-v3q9

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-v5pv-jmfg-52fm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-v8j2-h48g-gmvv

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

6 days ago

UPDATED

6 days ago

ADVISORY ID

MINI-v8wf-fg93-qq8c

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-vgh2-px44-g6wf

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-vh47-rcr2-4v67

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-vqj9-7mjr-qqxm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-vvcp-f7q9-97mw

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-w37c-74gh-5m5j

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-w7qj-h8h7-78mm

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

25 days ago

UPDATED

25 days ago

ADVISORY ID

MINI-wc2p-mpmq-jxjh

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-wcp7-895c-35rj

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-wg72-h3f4-hwcg

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

8 days ago

UPDATED

8 days ago

ADVISORY ID

MINI-wr69-56gx-27pw

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-x6v4-cwgm-gp2q

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY

minimos

CREATED

24 days ago

UPDATED

24 days ago

ADVISORY ID

MINI-xcvh-hxgh-rvm8

EXPLOITABILITY SCORE

EXPLOITS FOUND

COMMON WEAKNESS ENUMERATION (CWE)-

RATING UNAVAILABLE FROM ADVISORY