CVE-2024-34502

Name: CVE-2024-34502
Creator: NVD / NIST
Published: 2024-05-05T19:15:07.197+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.41%

Last modified Jun 17, 2026

CVE-2024-34502 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in WikibaseLexeme in MediaWiki before 1.39.6, 1.40.x before 1.40.2, and 1.41.x before 1.41.1. Loading Special:MergeLexemes will (attempt to) make an edit that merges the from-id to the to-id, even if the request was not a POST request, and even if it does not contain an edit token.. EPSS estimates a 0.41% chance of exploitation in the next 30 days.

Description

An issue was discovered in WikibaseLexeme in MediaWiki before 1.39.6, 1.40.x before 1.40.2, and 1.41.x before 1.41.1. Loading Special:MergeLexemes will (attempt to) make an edit that merges the from-id to the to-id, even if the request was not a POST request, and even if it does not contain an edit token.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.41%

32.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-352

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	< 1.39.6
Mediawiki	Mediawiki	>= 1.40.0, < 1.40.2
Mediawiki	Mediawiki	>= 1.41.0, < 1.41.1
Fedoraproject	Fedora	40

References

https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikibaseLexeme/+/1013359Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FU2FGUXXK6TMV6R52VRECLC6XCSQQISY/Mailing List, Third Party Advisory
https://phabricator.wikimedia.org/T357101Issue Tracking, Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikibaseLexeme/+/1013359Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FU2FGUXXK6TMV6R52VRECLC6XCSQQISY/Mailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FU2FGUXXK6TMV6R52VRECLC6XCSQQISY/
https://phabricator.wikimedia.org/T357101Issue Tracking, Vendor Advisory

Timeline

Published: May 5, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-34502?

How severe is CVE-2024-34502?

CVE-2024-34502 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.

How do I fix CVE-2024-34502?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-34502?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST