CVE-2020-26121

Name: CVE-2020-26121
Creator: NVD / NIST
Published: 2020-09-27T21:15:13.063+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.28%

Last modified Jun 17, 2026

CVE-2020-26121 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in the FileImporter extension for MediaWiki before 1.34.4. An attacker can import a file even when the target page is protected against "page creation" and the attacker should not be able to create it. EPSS estimates a 1.28% chance of exploitation in the next 30 days.

Description

An issue was discovered in the FileImporter extension for MediaWiki before 1.34.4. An attacker can import a file even when the target page is protected against "page creation" and the attacker should not be able to create it. This occurs because of a mishandled distinction between an upload restriction and a create restriction. An attacker cannot leverage this to overwrite anything, but can leverage this to force a wiki to have a page with a disallowed title.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.28%

66.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	< 1.34.4
Fedoraproject	Fedora	33

References

https://commons.wikimedia.org/w/index.php?oldid=454609892#File:Wiki.pngVendor Advisory
https://gerrit.wikimedia.org/r/q/Ib852a96afc4dca10516d0510e69c10f9892b351bPatch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/
https://phabricator.wikimedia.org/T262628Issue Tracking, Patch, Vendor Advisory
https://commons.wikimedia.org/w/index.php?oldid=454609892#File:Wiki.pngVendor Advisory
https://gerrit.wikimedia.org/r/q/Ib852a96afc4dca10516d0510e69c10f9892b351bPatch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/
https://phabricator.wikimedia.org/T262628Issue Tracking, Patch, Vendor Advisory

Timeline

Published: Sep 27, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26121?

How severe is CVE-2020-26121?

CVE-2020-26121 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.28% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26121?

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-2020-26121?

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

Scan your code now

Source: NVD / NIST