CVE-2026-107850: medium-severity vulnerability in contao
Contao: Improper access control in the preview links module
Published
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.3epss 0.2%
exploitation probability
0.2%top 92% of all CVEs
observed exploitation
nono source reports it
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module can list every tl_preview_link record, obtain signed share URLs created by other users, and use them to view unpublished pages with showUnpublished despite lacking page permission.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
contao · contaoRelated CVEs — contao
In the same product, most dangerous first.
CVE-2022-24899HIGHCross site scripting via canonical tagEPSS 4.5%CVE-2021-37626HIGHPHP file inclusion via insert tagsEPSS 1.3%CVE-2021-37627HIGHPrivilege escalation via form generatorEPSS 1.0%CVE-2012-4383—CVE-2012-4383EPSS 0.9%CVE-2023-29200MEDIUMcontao/core-bundle has path traversal vulnerability in the file managerEPSS 0.8%CVE-2024-28235HIGHContao possible cookie sharing with external domains while checking protected pages for broken linksEPSS 0.7%