# CVE-2026-90450: Incorrect Authorization in Malcolm

> Authenticated users can access unauthorized request handlers due to a fail-open authorization default, potentially leading to privilege escalation and data exposure.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/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:** 11 Sep 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-47x5-rf97-8ggr

## What is CVE-2026-90450?

CVE-2026-90450 is a medium-severity missing authorization vulnerability in CISA Malcolm, published on 11 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The application's role-authorization lookup defaults to granting access when a request handler's name is not present in its table of role requirements, rather than defaulting to deny. Any request handler that is not explicitly registered in this table is reachable by any authenticated user regardless of their assigned role, and any newly added handler is fail-open by default until explicitly added to the table.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-90450?


## How do I fix CVE-2026-90450?

No fix has been published for CVE-2026-90450 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90450 being exploited?

There is no known exploitation of CVE-2026-90450 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90450 and fix it if it is affected.

What it is: CVE-2026-90450 is a medium-severity missing authorization vulnerability in CISA Malcolm, published on 11 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-2026-90450 in the wild and no public exploit code.

Affected product: CISA Malcolm. 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-2026-90450/ (Markdown: https://insights.sbomify.com/CVE-2026-90450/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90450
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90450
- OSV: https://osv.dev/vulnerability/CVE-2026-90450

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90450/
Summaries are generated and may contain mistakes; the official description above is the record.