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OpenAdvisories
Low · 2.1 CVE-2026-45753 EUVD-2026-44344GHSA-hhg7-c65m-h7ff

Symfony: HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — javascript: URI Survives Sanitization (XSS)

Published Jul 14, 2026 · Updated Jul 14, 2026 · Assigned by GitHub_M

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, 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 products

VendorProductAffectedFixed
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 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 symfony 7.4.12+dfsg-1 —
Debian 13 symfony 6.4.41+dfsg-0+deb13u1 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 symfony No fix yet —
Ubuntu 26.04 LTS symfony No fix yet —
Ubuntu 25.10 symfony No fix yet —
Ubuntu 16.04 LTS symfony No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 24.04 LTS symfony No fix yet —
Ubuntu Pro 22.04 LTS symfony No fix yet —
Ubuntu Pro 20.04 LTS symfony No fix yet —
Ubuntu Pro 18.04 LTS symfony No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
Packagist symfony/html-sanitizer >= 6.1.0, < 6.4.40 6.4.40 GHSA-hhg7-c65m-h7ff
Packagist symfony/html-sanitizer >= 7.0.0, < 7.4.12 7.4.12 GHSA-hhg7-c65m-h7ff
Packagist symfony/html-sanitizer >= 8.0.0, < 8.0.12 8.0.12 GHSA-hhg7-c65m-h7ff
Packagist symfony/symfony >= 6.1.0, < 6.4.40 6.4.40 GHSA-hhg7-c65m-h7ff
Packagist symfony/symfony >= 7.0.0, < 7.4.12 7.4.12 GHSA-hhg7-c65m-h7ff
Packagist symfony/symfony >= 8.0.0, < 8.0.12 8.0.12 GHSA-hhg7-c65m-h7ff

References