Auth bypass in Misp
CVE-2026-56423
MISP Core contained broken access-control checks in the bulk deletion flows for Event Reports and Sharing Groups. The affected deleteSelection handlers authorized deletion using broad role-level permissions instead of validating authorization for each selected object. For Event Reports, EventReportsController::deleteSelection relied on the global perm_add capability rather than a per-report ownership/authorization check. As a result, a contributor-level user could submit report IDs or UUIDs for reports belonging to other organisations and hard-delete them instance-wide. The fix changed the callback to call EventReport::fetchIfAuthorized($user, $itemId, 'delete') for each selected report before deletion. For Sharing Groups, SharingGroupsController::deleteSelection relied on the global perm_sharing_group capability rather than verifying ownership of each selected sharing group. This allowed a sharing-group-capable user to hard-delete sharing groups owned by other organisations, bypassing the per-object ownership gate used by the single-object delete action. The fix changed the callback to call SharingGroup::checkIfOwner($user, $itemId) for each selected sharing group. An authenticated attacker with the relevant broad role permission could abuse the affected bulk deletion endpoints to delete objects outside their organisation’s authorization scope, causing loss of event-report content or sharing-group configuration across the instance.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (38.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Misp — versions 0
- Misp-Project Misp
Weakness classification (CWE)
Public proof-of-concept exploits
References
- 5a6e4751-2f3f-4070-9419-94fb35b644e8 (Patch, patch)
- 5a6e4751-2f3f-4070-9419-94fb35b644e8 (Patch, patch)
Frequently asked questions
- What is CVE-2026-56423?
- CVE-2026-56423 is a high-severity vulnerability in Misp, classified under Missing Authorization. CVSS score: 8.8/10. Published 2026-06-22.
- How severe is CVE-2026-56423?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2026-56423 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.