Quick answers
- Is CVE-2026-18422 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-18422 being exploited in the wild.
- How severe is CVE-2026-18422?
- Medium severity, with a CVSS score of 6.5, published 15 September 2026.
- Which products and versions are affected?
- Concrete CMS before 9.5.3.
- Is there a fix for CVE-2026-18422?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-18422 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-18422?
- Check whether you run Concrete CMS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a combined authorization check bypass and CSRF token validation failure in the Backend\Page\Multilingual::assign backend action. An authenticated user who holds the Edit Page Multilingual Settings permission on a single page can exploit the lack of destination-side authorization checks and CSRF token validation to bind an arbitrary page in another locale as a source page's translation, and delete legitimate translation pairs. Attack requires authentication and the attacker must already hold multilingual editing rights on at least one page. The impact is limited to language routing and translation relationship integrity rather than data exposure. Patched in Concrete CMS version 9.5.3 and later.
Affected products
- Concrete CMS Concrete CMS before 9.5.3
Timeline
- 2026-09-15: disclosed