CVE-2026-103858
MISP Incomplete Thread Authorization Allows Unauthorized Read and Post Access to Discussions
- State
- Published
- Severity
- 5.3 Medium
- Published
- Oct 1, 2026
- Updated
- Oct 1, 2026
- Reserved
- Oct 1, 2026
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
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N | CIRCL |
Weaknesses
- CWE-285 Improper Authorization
Affected Products
| Product | Versions |
|---|---|
MISPMISP |
|
References
- Security patchpatch
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