What’s Vulnerable › Vulnerabilities
CVE-2026-54398: MISP object edit authorization bypass allows unauthorized sharing group assignment
- Severity: medium (CVSS 5.3 v4.0)
- 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: 2026-06-12 · updated 2026-07-23
- Weakness: CWE-863
Description
An authorization flaw in MISP’s object add/edit handling allowed an authenticated user with object editing permissions to assign a MISP object, or attributes contained within an object, to a sharing group that the user was not authorized to use or view. When editing objects, the sharing group validation was performed against the wrong request data structure after object fields had been merged to the top level, causing the check to be bypassed. In addition, attributes embedded in objects were not individually validated for authorized sharing group use. An attacker could craft a request with distribution set to 4 and an arbitrary sharing_group_id, potentially disclosing the existence or name of otherwise non-visible sharing groups and improperly modifying the distribution metadata of objects or contained attributes.
Affected products
- MISP: before 2.5.40 — fixed in 2.5.40
How to fix
Upgrade to a fixed version: MISP 2.5.40. Check the vendor advisory for mitigations.
References
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