What’s Vulnerable › Vulnerabilities
CVE-2026-10855: MISP Event template importer authorization bypass
- Severity: medium (CVSS 4.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-06-04 · updated 2026-07-22
- Weakness: CWE-862
Description
An authorization flaw existed in the MISP Event Template Importer overwrite workflow. When importing an event template in overwrite mode, the application checked whether a matching template already existed but did not verify that the importing user belonged to the organization that owned the existing template. As a result, an authenticated user with access to the template import functionality could forcibly overwrite an event template owned by another organization. Successful exploitation could allow unauthorized modification of another organization’s event template, potentially altering template structure, attributes, or metadata used for subsequent event creation or sharing workflows. Site administrators are not affected by this restriction, as they are explicitly allowed to overwrite templates across organizations. The issue was fixed by enforcing an ownership check before overwrite: non-site-admin users may only overwrite templates owned by their own organization.
Affected products
- MISP: before 2.5.39 — fixed in 2.5.39
How to fix
Upgrade to a fixed version: MISP 2.5.39. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-10855 or the next vulnerability affects your stack