CVE-2026-18856 Poesis Rhymix CMS Data Import importer.admin.controller.php procImporterAdminCheckXmlFile server-side request forgery
Remote attackers can exploit a server-side request forgery vulnerability in the Rhymix CMS Data Import module to access internal resources.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18856?
CVE-2026-18856 is a medium-severity server-side request forgery vulnerability in Poesis Rhymix CMS, published on 5 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A vulnerability was determined in Poesis Rhymix CMS up to 2.1.33. This impacts the function procImporterAdminCheckXmlFile of the file modules/importer/importer.admin.controller.php of the component Data Import Module. This manipulation of the argument filename causes server-side request forgery. The attack is possible to be carried out remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 2.1.34 will fix this issue. It is recommended to upgrade the affected component.
Weakness: CWE-918
Which versions are affected by CVE-2026-18856?
How do I fix CVE-2026-18856?
No fix has been published for CVE-2026-18856 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-18856 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18856 exists.
Sources
Also known as GHSA-26jj-c4g2-h8m6.