Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-qc95-4862-92fh

Symfony has an HtmlSanitizer allowLinkHosts() / allowMediaHosts() Bypass via URL-Parser Differentials and <area> Misclassification

CVSS 2.3 LowEPSS 0.0034 · 27th percentile

Published by the GitHub Advisory Database at 27 May 2026, 20:13 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
symfony/html-sanitizerPackagist>=6.1.0, <6.4.40 || >=7.0.0, <7.4.12 || >=8.0.0, <8.0.126.4.40, 7.4.12, 8.0.12
symfony/symfonyPackagist>=6.1.0, <6.4.40 || >=7.0.0, <7.4.12 || >=8.0.0, <8.0.126.4.40, 7.4.12, 8.0.12
Identifiers
GHSA-qc95-4862-92fh · CVE-2026-45066 · PKSA-jwvg-gphd-brbz · PKSA-vty3-cvqg-rtn4
Weakness (CWE)
CWE-184 · CWE-436
Tags
Published
27 May 2026
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Symfony's symfony/html-sanitizer package (and the symfony/symfony package) is affected in versions from 6.1.0 before 6.4.40, from 7.0.0 before 7.4.12, and from 8.0.0 before 8.0.12. An attacker who can supply HTML content that the sanitizer processes can use crafted URLs to get past the allowLinkHosts(), allowLinkSchemes(), and media host restrictions, including by placing an area element's href outside the link policy. Upgrade to symfony/html-sanitizer 6.4.40, 7.4.12, or 8.0.12, or to the matching symfony/symfony release.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
2.3 Low 4.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0034, the 27th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:01 UTC First seen by agentprime
  2. 31 Oct 2026, 14:01 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.