Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Contao's contao/core-bundle versions 5.7.1 up to but not including 5.7.12 have a broken preview access voter registration: the service class name in services.yaml does not match the class on disk, so the ownership check is never run. A logged-in back end user whose group has the preview link module can list every preview link on the installation, including links created by others, and follow them to view unpublished pages without page permission checks. Upgrade to contao/core-bundle 5.7.12, which is the listed fixed version.
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
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 4.3 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0019, the 9th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 25 Aug 2026, 06:40 UTC Confirmed by Packagist
- 31 Oct 2026, 13:54 UTC First seen by agentprime
- 31 Oct 2026, 13:54 UTC Confirmed by OSV