medium6.1
CVE-2026-45753
Symfony's HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — `javascript`: URI Survives Sanitization (XSS)
Impact
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, UrlAttributeSanitizer::getSupportedAttributes() omits URL-valued attributes including action, formaction, poster, and cite, so configurations that admit those attributes can leave javascript: URIs unsanitized and enable XSS when the resulting HTML is rendered or a victim submits a form or clicks a button. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | symfony/html-sanitizer | >= 6.1.0, < 6.4.40 | 6.4.40 |
| composer | symfony/symfony | >= 6.1.0, < 6.4.40 | 6.4.40 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Sensiolabs | Symfony | from 6.1.0 before 6.4.40 from 7.0.0 before 7.4.12 from 8.0.0 before 8.0.12 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-hhg7-c65m-h7ff
- https://github.com/symfony/symfony/security/advisories/GHSA-hhg7-c65m-h7ff
- https://github.com/symfony/symfony/commit/26a598fcfc4f903cc55ff202f642ee621839825e
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/html-sanitizer/CVE-2026-45753.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45753.yaml
- https://symfony.com/cve-2026-45753
- https://github.com/symfony/symfony/commit/487728e7e180a674a6d4c01bd0cb56161cc441b7
- https://github.com/symfony/symfony/releases/tag/v6.4.40
- https://github.com/symfony/symfony/releases/tag/v7.4.12
- https://github.com/symfony/symfony/releases/tag/v8.0.12