---
id: "CVE-2026-121444"
kind: "vulnerability"
aliases: ["CVE-2026-121444"]
title: "svg-sanitizer: crafted SVG pins PHP workers for hours"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["composer", "package", "php", "svg-upload"]
not_affected_if: ["no-svg-uploads", "trusted-input-only"]
published_at: "2026-11-03T15:17:36+00:00"
first_seen_at: "2026-11-03T15:22:00+00:00"
updated_at: "2026-11-03T15:22:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121444", "first_seen_at": "2026-11-03T15:22:00+00:00"}]
---

# svg-sanitizer: crafted SVG pins PHP workers for hours

svg-sanitizer, a PHP library for cleaning SVG uploads, takes exponential time on a small crafted SVG with layered use elements. An attacker who can upload a file can tie up PHP workers for hours, causing denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Look for `svg-sanitizer` in `composer.lock` or `composer show svg-sanitizer`
- Check whether the installed version is between `0.11.0` and `1.1.0` (before `1.1.0`)

## Fix

- Move to `svg-sanitizer` `1.1.0` or later

## Timeline

- 2026-11-03T15:22:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121444

## Documents

- [advisory] Vendor advisory: github.com https://github.com/darylldoyle/svg-sanitizer/security/advisories/GHSA-hrwm-vcc9-hcm4
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/svg-sanitizer-0.11.0-before-1.1.0-algorithmic-complexity-dos-via-use-reference-graph

## From the sources

svg-sanitizer from 0.11.0 before 1.1.0 contains an algorithmic complexity denial of service vulnerability in hasInfiniteLoop() and countUse() of the use reference-graph analysis. Attackers can upload a small layered SVG with 15 levels of fanned-out use elements, forcing exponential path enumeration that pins PHP workers for hours.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_