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.
https://github.com/symfony/symfony/security/advisories/GHSA-qc95-4862-92fh
https://github.com/symfony/symfony/releases/tag/v8.0.12
https://github.com/symfony/symfony/releases/tag/v7.4.12
https://github.com/symfony/symfony/releases/tag/v6.4.40
https://github.com/symfony/symfony/commit/d506b556d3d3906f3e8660ad82257ce87edbaac4
Published: 2026-07-14
Updated: 2026-07-16
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 2.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Low
EPSS: 0.00048