CVE-2026-107850
mediumContao is an Open Source CMS.
Contao is an Open Source CMS. From version 5.7.1 until 5.7.12, core-bundle/config/services.yaml registers the preview access voter as Contao\CoreBundle\Security\Voter\DataContainer\PreviewAccessVoter although the shipped class is PreviewVoter. Symfony therefore omits voter autoconfiguration and removes the private service, so PreviewVoter::hasAccess() never enforces ownership. A non-admin backend user with the preview_link module can list every tl_preview_link record, obtain signed share URLs created by other users, and use them to view unpublished pages with showUnpublished despite lacking page permission. The advisory does not establish editing or deletion of foreign links. This issue is fixed in version 5.7.12.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/contao/contao/commit/6b483d380a4b2dc61432c4c697e411508f93bf91 security-advisories@github.com
- https://github.com/contao/contao/releases/tag/5.7.12 security-advisories@github.com
- https://github.com/contao/contao/security/advisories/GHSA-q6wp-fr43-gm9v security-advisories@github.com