# CVE-2026-54398: MISP object edit authorization bypass allows unauthorized sharing group assignment

> Authenticated users can bypass sharing group validation to assign objects to unauthorized groups, potentially disclosing group names and modifying distribution metadata.

- **Severity:** Medium 5.3 (`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`)
- **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:** 12 Jun 2026
- **Updated:** 15 Jun 2026
- **Also known as:** GHSA-27wx-pvwm-cfh2

## What is CVE-2026-54398?

CVE-2026-54398 is a medium-severity missing authorization vulnerability in misp, published on 12 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An authorization flaw in MISP’s object add/edit handling allowed an authenticated user with object editing permissions to assign a MISP object, or attributes contained within an object, to a sharing group that the user was not authorized to use or view. When editing objects, the sharing group validation was performed against the wrong request data structure after object fields had been merged to the top level, causing the check to be bypassed. In addition, attributes embedded in objects were not individually validated for authorized sharing group use.

An attacker could craft a request with distribution set to 4 and an arbitrary sharing_group_id, potentially disclosing the existence or name of otherwise non-visible sharing groups and improperly modifying the distribution metadata of objects or contained attributes.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-54398?


## How do I fix CVE-2026-54398?

No fix has been published for CVE-2026-54398 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54398 being exploited?

There is no known exploitation of CVE-2026-54398 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54398 and fix it if it is affected.

What it is: CVE-2026-54398 is a medium-severity missing authorization vulnerability in misp, published on 12 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-2026-54398 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-2026-54398/ (Markdown: https://insights.sbomify.com/CVE-2026-54398/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54398
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54398
- OSV: https://osv.dev/vulnerability/CVE-2026-54398

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54398/
Summaries are generated and may contain mistakes; the official description above is the record.