CVE-2026-91825
HIGH 7.1 ALL-YEARSAffected versions of MISP fail to authorize a submitted sharing group in a specific event-edit path. The vulnerable logic checked whether the acting user could use a sharing_group_id only when the request explicitly supplied distribution = 4. If the attacker instead omitted distribution but supplied a different sharing_group_id, that authorization branch was skipped. Later, MISP’s field-recovery logic restored the existing event distribution from storage. For events already configured with sharing-group distribution, the unauthorized sharing-group ID could therefore be saved. The fix adds authorization checks in both the controller and Event::_edit() whenever a non-empty sharing_group_id is supplied without distribution. The model now calls SharingGroup::checkIfAuthorised() before persisting the change. Version affected: ≤2.5.45
Severe if exploited (CVSS 7.1), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 31st percentile
Impact if exploited
7.1CVSS 4.0 · HIGH · CNA
- ConfidentialityLow
- IntegrityHigh
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
No public exploit or proof-of-concept code is catalogued for this CVE (no ExploitDB, Nuclei, or CISA-KEV entry). It may still exist — search GitHub or check the references below.
Weakness (CWE)
- CWE-862: Missing Authorization
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
All CVSS metrics
- HIGH 7.1 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N - HIGH 7.1 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X