CVE-2026-92760

Description

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