Auth bypass in Shlinkio Shlink
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (35.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/shlinkio/shlink/issues/2633 (issue-tracking)
- github.com/shlinkio/shlink (product)
- github.com/shlinkio/shlink/blob/v5.1.6/module/Rest/src/Action/MercureInfoAction… (technical-description)
- github.com/shlinkio/shlink-common/blob/main/src/Mercure/LcobucciJwtProvider.php (technical-description)
- www.vulncheck.com/advisories/shlink-through-5.1.6-mercure-token-authorization-b… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-92760?
- CVE-2026-92760 is a medium-severity vulnerability in Shlinkio Shlink, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-09-16.
- How severe is CVE-2026-92760?
- Medium severity. CVSS v3 base score is 6.5 out of 10.