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.)
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | mediawiki | 1:1.35.1-1 | — |
| Debian 13 | mediawiki | 1:1.35.1-1 | — |
| Debian 12 | mediawiki | 1:1.35.1-1 | — |
| Debian 10 | mediawiki | 1:1.31.12-1~deb10u1 | DSA-4816-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | mediawiki | No fix yet | — |
| Ubuntu 26.04 LTS | mediawiki | No fix yet | — |
| Ubuntu 25.10 | mediawiki | No fix yet | — |
| Ubuntu 18.04 LTS | mediawiki | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | mediawiki | No fix yet | — |
| Ubuntu Pro 22.04 LTS | mediawiki | No fix yet | — |
| Ubuntu Pro 20.04 LTS | mediawiki | No fix yet | — |
Advisories 1
- DSA-4816-1 mediawiki - security update Debian Security (DSA / DLA) · Mar 9, 2026