CVE-2026-18736Public exploitNetwork attack vector

Internal HTML-title disclosure via unrestricted URL fetch

Published Aug 3, 2026 · Updated Aug 3, 2026

SSRF in Shlink 2.6.0 through 5.1.5 allows remote authenticated users to read internal HTML titles through short URL creation. ShortUrlTitleResolutionHelper fetches the caller-supplied long URL without host restrictions or private-address checks and follows up to 15 redirects. A valid API key and the non-default title auto-resolution setting are required; disclosure is limited to the title of HTML responses.

CVSS severity5.3
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Shlink 2.6.0 through 5.1.5 allows remote authenticated users to read internal HTML titles through short URL creation. ShortUrlTitleResolutionHelper fetches the caller-supplied long URL without host restrictions or private-address checks and follows up to 15 redirects. A valid API key and the non-default title auto-resolution setting are required; disclosure is limited to the title of HTML responses.

The record

CVE
CVE-2026-18736
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
Shlink
Product
Shlink
Classifications
CWE-918, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.0 <=5.1.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shlink · Shlinkversion=2.6.0 <=5.1.5

Published CVSS scores

5.0VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
5.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

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Technologies

Your stack

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Your stack

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