What’s Vulnerable › Vulnerabilities

CVE-2020-25828

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-09-27 · updated 2026-06-17
• Weakness: CWE-79

Description

An issue was discovered in MediaWiki before 1.31.10 and 1.32.x through 1.34.x before 1.34.4. The non-jqueryMsg version of mw.message().parse() doesn't escape HTML. This affects both message contents (which are generally safe) and the parameters (which can be based on user input). (When jqueryMsg is loaded, it correctly accepts only whitelisted tags in message contents, and escapes all parameters. Situations with an unloaded jqueryMsg are rare in practice, but can for example occur for Special:SpecialPages on a wiki with no extensions installed.)

Affected products

• Fedoraproject Fedora: 33
• Wikimedia Foundation MediaWiki: from 1.32.0 before 1.34.4; 1.31.10 — fixed in 1.34.4

How to fix

Upgrade to a fixed version: Wikimedia Foundation MediaWiki 1.34.4. Check the vendor advisory for mitigations.

References

• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/
• https://lists.wikimedia.org/pipermail/mediawiki-announce
• https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html
• https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/
• https://lists.wikimedia.org/pipermail/mediawiki-announce
• https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html
• https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html

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