What’s Vulnerable › Vulnerabilities

CVE-2026-18736: Shlink Server-Side Request Forgery via Short URL Title Auto-Resolution

• Severity: medium (CVSS 5.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-03 · updated 2026-10-23
• Weakness: CWE-918

Description

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.

Affected products

• shlinkio Shlink: all versions

References

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

Get alerted when CVE-2026-18736 or the next vulnerability affects your stack