CVE-2020-35477

Name: CVE-2020-35477
Creator: NVD / NIST
Published: 2020-12-18T08:15:15.23+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.51%

Last modified Jun 17, 2026

CVE-2020-35477 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. MediaWiki before 1.35.1 blocks legitimate attempts to hide log entries in some situations. If one sets MediaWiki:Mainpage to Special:MyLanguage/Main Page, visits a log entry on Special:Log, and toggles the "Change visibility of selected log entries" checkbox (or a tags checkbox) next to it, there is a redirection to the main page's action=historysubmit (instead of the desired behavior in which a revision-deletion form appears).. EPSS estimates a 1.51% chance of exploitation in the next 30 days.

Description

MediaWiki before 1.35.1 blocks legitimate attempts to hide log entries in some situations. If one sets MediaWiki:Mainpage to Special:MyLanguage/Main Page, visits a log entry on Special:Log, and toggles the "Change visibility of selected log entries" checkbox (or a tags checkbox) next to it, there is a redirection to the main page's action=historysubmit (instead of the desired behavior in which a revision-deletion form appears).

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

1.51%

71.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-670

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	< 1.35.1
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Fedoraproject	Fedora	33

References

https://lists.debian.org/debian-lts-announce/2020/12/msg00034.htmlMailing List, Third 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/T205908Exploit, Issue Tracking, Third Party Advisory
https://www.debian.org/security/2020/dsa-4816Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00034.htmlMailing List, Third 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/T205908Exploit, Issue 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-2020-35477?

How severe is CVE-2020-35477?

CVE-2020-35477 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.51% probability of exploitation in the next 30 days.

How do I fix CVE-2020-35477?

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-2020-35477?

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

Scan your code now

Source: NVD / NIST