CVE-2026-18736

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 61/100
Published: 2026-08-03 Modified: 2026-10-23 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: X
AT: None
VC: Low
VI: None
VA: None

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.

Weakness Classification (1)

Bug Bounty Relevance

61 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.33%
Raw Score 0.003310
Percentile 26.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00331
2026-10-28
0.00331

Intelligence Sources

nvd ref →