CVE-2026-77609 — mediawiki/semantic-media-…
MEDIUMCVE-2026-77609 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in mediawiki/semantic-media-wiki. A fix is available for mediawiki/semantic-media-wiki — see the affected versions and patch details below.
Semantic MediaWiki has an open redirect in Special:URIResolver
Real-World Exposure
mediawiki/semantic-media-wikiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Failure mode
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.
Remediation
- The resolved target URL is parsed and compared against the current host at the redirect sink.
- The redirect is rejected (bad-title error page) when a user or pass component is present, or when the host does not match the current host.
Maintenance note
Redirect code must validate the final target URL, not just the input path. Host comparison belongs at the redirect sink: each sink (special page, entry point) must validate its own target rather than relying on upstream normalisation.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | mediawiki/semantic-media-wiki | all versions | 7.2.0composer require mediawiki/semantic-media-wiki:^7.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mediawiki/semantic-media-wiki, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mediawiki/semantic-media-wiki to 7.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-77609 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-77609 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-77609. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-77609 in your dependencies?
O3 Security finds CVE-2026-77609 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.