What’s Vulnerable › Vulnerabilities
CVE-2026-103858: MISP Incomplete Thread Authorization Allows Unauthorized Read and Post Access to Discussions
- 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: 2026-10-01 · updated 2026-10-01
- Weakness: CWE-285
Description
MISP contains an incomplete authorization check in the discussion posting functionality. When a user submits a post to a thread or replies to an existing post, the application only verified whether the target thread was restricted to a single organization (org-only distribution). It did not enforce the full thread access control list, including sharing-group membership and event-level visibility. As a result, an authenticated user who is outside the relevant sharing group or who does not have visibility on the associated event could: - Read the thread title and the content of the quoted post - Submit a new post into the discussion thread This constitutes both an information disclosure (reading restricted thread and post content) and an integrity issue (injecting content into a thread the user is not authorized to participate in). Affected: <2.5.48
Affected products
- MISP: before 2.5.48 — fixed in 2.5.48
How to fix
Upgrade to a fixed version: MISP 2.5.48. Check the vendor advisory for mitigations.
References
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