SQL Injection in Shlinkio Shlink
CVE-2026-18737
Shlink contains a blind SQL injection vulnerability that allows any authenticated API key holder to inject arbitrary SQL fragments by supplying an unvalidated direction value in the orderBy query parameter of the tag statistics endpoint. Attackers can craft a malicious direction string containing SQL subqueries that flows unsanitized into a Doctrine QueryBuilder ORDER BY clause, enabling time-based, boolean-oracle, and error-based extraction of sensitive data including long URLs, visitor records, IP addresses, geolocation data, user agents, and hashed API key secrets from any tenant.
Vulnerability class: SQL Injection
EPSS: 0.003 (23.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Shlinkio Shlink — versions 3.3.1
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-18737?
- CVE-2026-18737 is a medium-severity vulnerability in Shlinkio Shlink, classified under SQL Injection. CVSS score: 6.5/10. Published 2026-08-03.
- How severe is CVE-2026-18737?
- Medium severity. CVSS v3 base score is 6.5 out of 10.