Vulnerability · Published Jul 14, 2026 · Assigned by GitHub_M
CVE-2026-45066Symfony: HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification
Low 2.3
In plain English
A low-severity security flaw in html-sanitizer from symfony. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | symfony | 6.4.41+dfsg-0+deb13u1 | DEBIAN-CVE-2026-45066 |
| Debian:14 | symfony | 7.4.12+dfsg-1 | DEBIAN-CVE-2026-45066 |
| Packagist | symfony/html-sanitizer | 6.4.40 | GHSA-qc95-4862-92fh |
| Packagist | symfony/html-sanitizer | 7.4.12 | GHSA-qc95-4862-92fh |
| Packagist | symfony/html-sanitizer | 8.0.12 | GHSA-qc95-4862-92fh |
| Packagist | symfony/symfony | 8.0.12 | GHSA-qc95-4862-92fh |
| Packagist | symfony/symfony | 6.4.40 | GHSA-qc95-4862-92fh |
| Packagist | symfony/symfony | 7.4.12 | GHSA-qc95-4862-92fh |
| Ubuntu:25.10 | symfony | no fix listed | UBUNTU-CVE-2026-45066 |
| Ubuntu:26.04:LTS | symfony | no fix listed | UBUNTU-CVE-2026-45066 |
| Ubuntu:26.10 | symfony | no fix listed | UBUNTU-CVE-2026-45066 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| symfony | symfony | >= 6.1.0-BETA1, < 6.4.40>= 7.0.0-BETA1, < 7.4.12>= 8.0.0-BETA1, < 8.0.12 |
| symfony | html-sanitizer | >= 6.1.0-BETA1, < 6.4.40>= 7.0.0-BETA1, < 7.4.12>= 8.0.0-BETA1, < 8.0.12 |
Weakness: CWE-184, CWE-436 · 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
References
- https://github.com/symfony/symfony/security/advisories/GHSA-qc95-4862-92fh x_refsource_CONFIRM
- https://github.com/symfony/symfony/commit/d506b556d3d3906f3e8660ad82257ce87edbaac4 x_refsource_MISC
- https://github.com/symfony/symfony/releases/tag/v6.4.40 x_refsource_MISC
- https://github.com/symfony/symfony/releases/tag/v7.4.12 x_refsource_MISC
- https://github.com/symfony/symfony/releases/tag/v8.0.12 x_refsource_MISC