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TI-2026-15354 Aliases CVE-2026-18736GHSA-c6g4-pfhg-gvmp

Shlink Server-Side Request Forgery via Short URL Title Auto-Resolution

Priority MEDIUM 57CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.

Summary

Shlink contains a server-side request forgery vulnerability that allows authenticated API key holders to cause the server to issue arbitrary HTTP GET requests by supplying a crafted long URL during short URL creation with title auto-resolution enabled. Attackers can submit URLs pointing to public hosts that redirect to internal targets, including loopback addresses, link-local ranges, and cloud metadata endpoints such as 169.254.169.254, to exfiltrate internal service information via the HTML title element returned in the short URL creation response.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00331 26th 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

No affected products listed by the sources yet.

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-18736
  2. 2026-10-03 Alias added: GHSA-c6g4-pfhg-gvmp

References

Advisory 1

Other 1

  • TI-2026-62505 Shlink through 5.1.6 Mercure Token Authorization Bypass CVSS 4.0HIGH 7.1
  • TI-2026-15355 Shlink Blind SQL Injection via tags/stats orderBy Parameter CVSS 4.0HIGH 7.1
  • TI-2026-15356 Shlink CSV Formula Injection via Visit Export CLI CVSS 4.0MEDIUM 5.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences