CVE-2020-35475

Name: CVE-2020-35475
Creator: NVD / NIST
Published: 2020-12-18T08:15:15.137+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.57%

Last modified Jun 17, 2026

CVE-2020-35475 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In MediaWiki before 1.35.1, the messages userrights-expiry-current and userrights-expiry-none can contain raw HTML. XSS can happen when a user visits Special:UserRights but does not have rights to change all userrights, and the table on the left side has unchangeable groups in it. EPSS estimates a 1.57% chance of exploitation in the next 30 days.

Description

In MediaWiki before 1.35.1, the messages userrights-expiry-current and userrights-expiry-none can contain raw HTML. XSS can happen when a user visits Special:UserRights but does not have rights to change all userrights, and the table on the left side has unchangeable groups in it. (The right column with the changeable groups is not affected and is escaped correctly.)

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.57%

72.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	< 1.35.1
Debian	Debian Linux	10.0
Fedoraproject	Fedora	33

References

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STT5Z4A3BCXVH3WIPICWU2FP4IPIMUPC/
https://lists.wikimedia.org/pipermail/mediawiki-announce/2020-December/000268.htmlMailing List, Release Notes, Vendor Advisory
https://phabricator.wikimedia.org/T268917Issue Tracking, Third Party Advisory
https://www.debian.org/security/2020/dsa-4816Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STT5Z4A3BCXVH3WIPICWU2FP4IPIMUPC/
https://lists.wikimedia.org/pipermail/mediawiki-announce/2020-December/000268.htmlMailing List, Release Notes, Vendor Advisory
https://phabricator.wikimedia.org/T268917Issue Tracking, Third Party Advisory
https://www.debian.org/security/2020/dsa-4816Third Party Advisory

Timeline

Published: Dec 18, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-35475?

How severe is CVE-2020-35475?

CVE-2020-35475 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.57% probability of exploitation in the next 30 days.

How do I fix CVE-2020-35475?

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-2020-35475?

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

Scan your code now

Source: NVD / NIST