Vulnerability Description
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986 while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Sensiolabs | Symfony | >= 6.1.0, < 6.4.40 |
Related Weaknesses (CWE)
References
- https://github.com/symfony/symfony/commit/d506b556d3d3906f3e8660ad82257ce87edbaaPatch
- https://github.com/symfony/symfony/releases/tag/v6.4.40ProductRelease Notes
- https://github.com/symfony/symfony/releases/tag/v7.4.12ProductRelease Notes
- https://github.com/symfony/symfony/releases/tag/v8.0.12ProductRelease Notes
- https://github.com/symfony/symfony/security/advisories/GHSA-qc95-4862-92fhPatchVendor Advisory
FAQ
What is CVE-2026-45066?
CVE-2026-45066 is a vulnerability with a CVSS score of 6.1 (MEDIUM). Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowl...
How severe is CVE-2026-45066?
CVE-2026-45066 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45066?
Check the references section above for vendor advisories and patch information. Affected products include: Sensiolabs Symfony.