CVE-2021-44855

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-12-26 · updated 2026-06-17
Weakness: CWE-79

Description

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. There is Blind Stored XSS via a URL to the Upload Image feature.

Affected products

Wikimedia Foundation MediaWiki: before 1.35.5; from 1.36.0 before 1.36.3; 1.37.0, 1.37.0-rc0, 1.37.0-rc1, 1.37.0-rc2 — fixed in 1.35.5, 1.36.3

How to fix

Upgrade to a fixed version: Wikimedia Foundation MediaWiki 1.35.5, 1.36.3. Check the vendor advisory for mitigations.

References

https://phabricator.wikimedia.org/T293589
https://security.gentoo.org/glsa/202305-24
https://phabricator.wikimedia.org/T293589
https://security.gentoo.org/glsa/202305-24

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