CVE-2026-92760
Shlink through 5.1.6 fails to enforce API key role restrictions when issuing Mercure subscription tokens, allowing restricted keys to subscribe to all topics. Attackers with author-only or domain-only keys can access the mercure-info endpoint to receive visit data including referrer, user agent, geolocation, and full short URL objects for URLs outside their authorization boundary.
Weakness
Shlink through 5.1.6 fails to enforce API key role restrictions when issuing Mercure subscription tokens, allowing restricted keys to subscribe to all topics. Attackers with author-only or domain-only keys can access the mercure-info endpoint to receive visit data including referrer, user agent, geolocation, and full short URL objects for URLs outside their authorization boundary.
References
- https://github.com/shlinkio/shlink
- https://github.com/shlinkio/shlink-common/blob/main/src/Mercure/LcobucciJwtProvider.php#L38-L41
- https://github.com/shlinkio/shlink/blob/v5.1.6/module/Rest/src/Action/MercureInfoAction.php#L26-L42
- https://github.com/shlinkio/shlink/issues/2633
- https://www.vulncheck.com/advisories/shlink-through-5.1.6-mercure-token-authorization-bypass
- https://github.com/shlinkio/shlink/issues/2633
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