Contao: Improper access control in the preview links module — GHSA-Q6WP-FR43-GM9V

Summary

`core-bundle/config/services.yaml` registers the preview access voter with the class `Contao\CoreBundle\Security\Voter\DataContainer\PreviewAccessVoter`, but the class shipped on disk is named `PreviewVoter`. Symfony resolves the class with `getReflectionClass($class, false)`, gets `null`, silently skips the interface based autoconfiguration that would have tagged it as a voter, and the now untagged private service…

Timeline

Published by source

2026-10-09

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 4.3 out of 10.
• Review exposure for the affected product or family: composer: contao/core-bundle.

Product

composer: contao/core-bundle

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-Q6WP-FR43-GM9V

Source

GitHub

Vendor

GitHub

Published by source

2026-10-09

Last source activity

2026-10-09

Additional identifiers

CVE-2026-107850

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.