CVE-2021-35197 Missing authorization in n/a

What is CVE-2021-35197?

CVE-2021-35197 is a high-severity missing authorization vulnerability in Debian Debian Linux, published on 2 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In MediaWiki before 1.31.15, 1.32.x through 1.35.x before 1.35.3, and 1.36.x before 1.36.1, bots have certain unintended API access. When a bot account has a "sitewide block" applied, it is able to still "purge" pages through the MediaWiki Action API (which a "sitewide block" should have prevented).

Weakness: CWE-863

Which versions are affected by CVE-2021-35197?

1 open source package ship an affected version, including mediawiki. It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Mediawiki Mediawiki.

How do I fix CVE-2021-35197?

Upgrade mediawiki to a fixed version for your release line: 1.31.15, 1.35.3 or 1.36.1.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-35197 being exploited?

There is no known exploitation of CVE-2021-35197 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-mediawiki-2021-35197, DEBIAN-CVE-2021-35197, GHSA-8hhg-q8jv-q9c7, MGASA-2021-0346, UBUNTU-CVE-2021-35197.