CVE-2026-18736

MEDIUM 5.0

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

CVSS Score

5.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-918
Vendor	shlinkio
Product	shlink
Published	Aug 3, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

None

Availability

None

Affected Versions

shlinkio / Shlink

2.6.0 ≤ 5.1.5

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/theopaid/Server-side-request-forgery-through-short-URL-title-resolution-shlink- github.com: https://github.com/shlinkio/shlink vulncheck.com: https://www.vulncheck.com/advisories/shlink-server-side-request-forgery-via-short-url-title-auto-resolution

Credits

Theodosis Paidakis