Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Medium, CVSS 6.6

Symfony's Cas2Handler Derives CAS service URL from Client Host Header → Cross-Service Ticket Replay

CVE-2026-45074GHSA-j8gj-9rm5-4xhx

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (symfony/symfony 8.0.12, 7.4.12; symfony/security-http 8.0.12, 7.4.12), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Packagist symfony/symfony

    Affected
    >= 7.1.0, < 7.4.12>= 8.0.0, < 8.0.12
    Fixed in
    8.0.12, 7.4.12

  • Packagist symfony/security-http

    Affected
    >= 7.1.0, < 7.4.12>= 8.0.0, < 8.0.12
    Fixed in
    8.0.12, 7.4.12

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
6.6 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U · score source
EPSS
  • CVE-2026-45074: 0.49% estimated exploitation activity in the next 30 days; percentile 42.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Cas2Handler builds this service parameter from Request::getSchemeAndHttpHost(), which reflects the attacker-controlled HTTP Host header whenever Symfony's framework.trustedhosts setting is not configured (the default). An attacker who controls any other application registered with the same CAS server can replay a victim's ticket against the Symfony application, with a spoofed Host header, and be authenticated as that victim. Resolution A new required serviceurl configuration option is introduced on Cas2Handler. The CAS service parameter sent to the validation endpoint is now built from this configured URL instead of being derived from the request's Host header, preventing cross-service ticket replay via Host header spoofing. The patch for this issue is available here for branch 7.4. Credits Symfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and Nicolas Grekas for providing the fix.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-j8gj-9rm5-4xhx

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-45074

Advisory: Symfony's Cas2Handler Derives CAS service URL from Client Host Header → Cross-Service Ticket Replay
IDs: CVE-2026-45074, GHSA-j8gj-9rm5-4xhx
Record: https://patchnext.com/advisories/cve-2026-45074 (revision 1, source checked 26 Oct 2026, 14:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: symfony/symfony 8.0.12, 7.4.12; symfony/security-http 8.0.12, 7.4.12. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist symfony/symfony: affected >= 7.1.0, < 7.4.12; >= 8.0.0, < 8.0.12; fixed in 8.0.12, 7.4.12
- Packagist symfony/security-http: affected >= 7.1.0, < 7.4.12; >= 8.0.0, < 8.0.12; fixed in 8.0.12, 7.4.12

## Suggested inspection (read-only)
- Packagist symfony/symfony: check the installed version with your package manager.
- Packagist symfony/security-http: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on symfony/symfony, symfony/security-http.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j8gj-9rm5-4xhx (GitHub-reviewed advisory GHSA-j8gj-9rm5-4xhx lists affected ranges: Packagist symfony/security-http >=7.1.0 =8.0.0 =7.1.0 =8.0.0 <8.0.12)

Commands are suggestions: review each one before running it.

Loading voting…