Quick answers
- Is CVE-2026-68533 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-68533 being exploited in the wild.
- How severe is CVE-2026-68533?
- Informational severity, with a CVSS score of 2.3, published 15 September 2026.
- Which products and versions are affected?
- Concrete CMS below 9.5.3.
- Is there a fix for CVE-2026-68533?
- A patch was published on 2026-09-15: Fixed in version 9.5.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-68533 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-68533?
- 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
This is an authorization bypass vulnerability in the conversation attachment upload endpoint (CVE-2026-68533). The root cause is that the "Add Message Attachments" permission check occurs after files have been imported into the file manager, rather than before. An attacker with a low-privilege user account lacking the attachment permission, or an unauthenticated visitor on a guest-posting configuration, can exploit the endpoint to upload and store files of allowed types. The attack requires network access to the endpoint and either valid user credentials or a guest-posting setup; no special user interaction is needed. An attacker can successfully import approved file types into the file manager despite lacking authorization. The vulnerability was patched in Concrete CMS 9.5.3.
Affected products
- Concrete CMS Concrete CMS below 9.5.3
Timeline
- 2026-09-15: disclosed
- 2026-09-15: patched: Fixed in version 9.5.3