# CVE-2026-95671: MISP Collections: Missing Authorization Check for Sharing Group on PUT Request in collections/add

> Authenticated users can bypass sharing group authorization checks via PUT requests, exposing data to unauthorized groups in MISP.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N`)
- **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 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-ph85-5rm4-24r5

## What is CVE-2026-95671?

CVE-2026-95671 is a medium-severity missing authorization vulnerability in MISP, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In MISP, the CollectionsController add() method enforced the sharing-group usability authorization check and element capture only when the HTTP request method was POST. However, the underlying CRUDComponent::add() method persists data on both POST and PUT requests. As a result, an authenticated user could issue a PUT request to the collections/add endpoint, bypassing the sharing-group authorization check entirely. This allowed the creation of a collection with distribution=4 (shared with a specific sharing group) targeting a sharing group that the user was not authorized to use. The bypassed check would normally verify that the current user has access to the specified sharing group before allowing the collection to be associated with it.

The security impact is that an authenticated user can place collection data into a sharing group context they do not have legitimate access to, potentially exposing that data to all members of the unauthorized sharing group and violating the intended access-control boundaries of the MISP instance.

The vulnerability requires an authenticated session and knowledge of a valid sharing group identifier; no user interaction or special tooling is needed beyond sending a PUT request instead of a POST request to the same endpoint.

Weakness: CWE-862 (Missing Authorization), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-95671?


## How do I fix CVE-2026-95671?

No fix has been published for CVE-2026-95671 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-95671 being exploited?

There is no known exploitation of CVE-2026-95671 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-95671 and fix it if it is affected.

What it is: CVE-2026-95671 is a medium-severity missing authorization vulnerability in MISP, published on 22 Sep 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-2026-95671 in the wild and no public exploit code.

Affected product: 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-2026-95671/ (Markdown: https://insights.sbomify.com/CVE-2026-95671/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-95671
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-95671
- OSV: https://osv.dev/vulnerability/CVE-2026-95671

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-95671/
Summaries are generated and may contain mistakes; the official description above is the record.