---
id: CVE-2026-18736
title: >-
  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-reso…
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-reso…
severity: medium
cvss: 5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N'
cwe:
  - CWE-918
published: '2026-08-03'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:35:08.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18736'
references:
  - url: 'https://github.com/shlinkio/shlink'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/theopaid/Server-side-request-forgery-through-short-URL-title-resolution-shlink-
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/shlink-server-side-request-forgery-via-short-url-title-auto-resolution
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/theopaid/Server-side-request-forgery-through-short-URL-title-resolution-shlink-
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00305
epssPercentile: 0.20736
ingestedAt: '2026-09-09T21:22:45.522Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.