Quick answers
- Is CVE-2026-18423 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-18423 being exploited in the wild.
- How severe is CVE-2026-18423?
- High severity, with a CVSS score of 7.1, published 15 September 2026.
- Which products and versions are affected?
- Concrete CMS 9.0.0 through 9.5.2.
- Is there a fix for CVE-2026-18423?
- 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-2026-18423 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-18423?
- 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 insecure direct object reference (IDOR) vulnerability in the Express saved search preset delete and edit dialogs. An authenticated user with only view permission on a single Express entity can exploit missing authorization checks to delete or rename saved search presets owned by other Express entities. The vulnerability affects versions 9.0.0 through 9.5.2. No user interaction is required; the attack is performed over the network by an authenticated attacker. A renamed preset name is returned to users of the targeted entity, enabling defacement or social engineering campaigns.
Affected products
- Concrete CMS Concrete CMS 9.0.0 through 9.5.2
Timeline
- 2026-09-15: disclosed