Shlink through 5.1.6 Mercure Token Authorization Bypass
Priority MEDIUM 64CWE-863Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00415 36th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-92760
- 2026-10-03 Alias added: GHSA-r72g-8wq6-6m7w
References
More shlinkio vulnerabilities
- TI-2026-15355 Shlink Blind SQL Injection via tags/stats orderBy Parameter CVSS 4.0HIGH 7.1
- TI-2026-15354 Shlink Server-Side Request Forgery via Short URL Title Auto-Resolution CVSS 4.0MEDIUM 5.3
- TI-2026-15356 Shlink CSV Formula Injection via Visit Export CLI CVSS 4.0MEDIUM 5.1
Sources
- CVE-2026-92760 · CVE Program
- CVE-2026-92760 · NVD
- FIRST EPSS
- GHSA-r72g-8wq6-6m7w · GitHub Advisory Database · CC BY 4.0
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