CVE-2026-77609 Semantic MediaWiki has an open redirect in Special:URIResolver
An open redirect in Semantic MediaWiki allows attackers to redirect users to malicious sites via crafted subpages, facilitating phishing attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-77609?
CVE-2026-77609 is a medium-severity vulnerability in SemanticMediaWiki, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Semantic MediaWiki is a free, open-source extension to MediaWiki that lets users store and query data within the wiki's pages. Prior to version 7.2.0, `Special:URIResolver` resolves its user-controlled subpage to a MediaWiki title and issues an HTTP 303 redirect to `$title->getFullURL()` without validating the resolved target. A crafted subpage can make that target point off-host: an interwiki prefix redirects to the foreign wiki (for example `Special:URIResolver/mw-3AFoo`, which decodes to `mw:Foo`, redirects to `https://www.mediawiki.org/wiki/Foo`), and where the resolved URL carries an authority the target can even embed `user:pass@host` credentials. The result is an open redirect to an attacker-influenced host, usable for phishing from a trusted wiki URL. Version 7.2.0 fixes the issue.
Weakness: CWE-601
Which versions are affected by CVE-2026-77609?
2 open source packages ship an affected version, including mediawiki/semantic-media-wiki.
| Package | Affected | Fixed in |
|---|---|---|
mediawiki/semantic-media-wiki Packagist | All versions | 7.2.0 |
mediawiki/semantic-media-wiki Packagist | All versions | 7.2.0 |
How do I fix CVE-2026-77609?
Upgrade mediawiki/semantic-media-wiki to 7.2.0 or later.
Is CVE-2026-77609 being exploited?
There is no known exploitation of CVE-2026-77609 in the wild and no public exploit code.
Sources
Also known as GHSA-hw3m-8j5x-94ff.