# CVE-2026-56423: Missing authorization in misp

> Authenticated users can delete event reports and sharing groups belonging to other organizations due to missing per-object authorization checks in bulk deletion endpoints.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jun 2026
- **Updated:** 23 Jun 2026
- **Also known as:** GHSA-3vhv-jx5j-gj6p

## What is CVE-2026-56423?

CVE-2026-56423 is a critical missing authorization vulnerability in Misp-Project Misp, published on 22 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-56423?

It affects 1 product.


Products: Misp-Project Misp.

## How do I fix CVE-2026-56423?

No fix has been published for CVE-2026-56423 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56423 being exploited?

There is no known exploitation of CVE-2026-56423 in the wild and no public exploit code.

Public exploit code:

- PoC for CVE-2026-56423: MISP deleteSelection broken access control (CWE-862, contributor hard-deletes other orgs' Event Reports/Sharing Groups, CVSS 8.8) (github_poc): https://github.com/BiiTts/CVE-2026-56423-MISP-deleteSelection-BrokenAccessControl

## Other vulnerabilities in Misp-Project Misp

- [CVE-2024-46918](https://insights.sbomify.com/CVE-2024-46918/): Missing authorization in n/a (critical 9.8)
- [CVE-2024-45509](https://insights.sbomify.com/CVE-2024-45509/): Missing authorization in n/a (critical 9.8)
- [CVE-2024-29858](https://insights.sbomify.com/CVE-2024-29858/): File upload in n/a (critical 9.8)
- [CVE-2024-29859](https://insights.sbomify.com/CVE-2024-29859/): File upload in n/a (critical 9.8)
- [CVE-2024-25674](https://insights.sbomify.com/CVE-2024-25674/): File upload in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56423 and fix it if it is affected.

What it is: CVE-2026-56423 is a critical missing authorization vulnerability in Misp-Project Misp, published on 22 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56423 in the wild and no public exploit code.

Affected product: Misp-Project Misp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-56423/ (Markdown: https://insights.sbomify.com/CVE-2026-56423/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56423
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56423
- OSV: https://osv.dev/vulnerability/CVE-2026-56423

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56423/
Summaries are generated and may contain mistakes; the official description above is the record.