CVE-2026-10855 MISP Event template importer authorization bypass
Authenticated users can overwrite event templates owned by other organizations due to missing ownership checks, allowing unauthorized data modification.
- 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-2026-10855?
CVE-2026-10855 is a medium-severity missing authorization vulnerability in Misp-Project Misp, published on 4 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-862
Which versions are affected by CVE-2026-10855?
It affects 1 product.
Products include Misp-Project Misp.
How do I fix CVE-2026-10855?
No fix has been published for CVE-2026-10855 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-10855 being exploited?
There is no known exploitation of CVE-2026-10855 in the wild and no public exploit code.
Other vulnerabilities in Misp-Project Misp
Sources
Also known as GHSA-243v-5f97-vfq3.