# CVE-2026-90443: Cross-site Scripting in Malcolm

> Unauthenticated attackers can execute arbitrary scripts and redirect users via crafted links in the Malcolm web interface, potentially compromising user sessions.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 Sep 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-w76j-wwhj-ch25

## What is CVE-2026-90443?

CVE-2026-90443 is a medium-severity cross-site scripting vulnerability in CISA Malcolm, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A web interface reflects a portion of the request URL into a script context and a hyperlink attribute without adequate encoding, and does not require authentication to reach. This allows an unauthenticated network attacker to craft a link that, when visited by a user, executes arbitrary script in the context of the affected application and can redirect the user's browser to an arbitrary external site. Successful exploitation could allow an attacker to act with the compromised user's session privileges within the application.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-90443?


## How do I fix CVE-2026-90443?

No fix has been published for CVE-2026-90443 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90443 being exploited?

There is no known exploitation of CVE-2026-90443 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90443 and fix it if it is affected.

What it is: CVE-2026-90443 is a medium-severity cross-site scripting vulnerability in CISA Malcolm, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-90443 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-2026-90443/ (Markdown: https://insights.sbomify.com/CVE-2026-90443/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90443
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90443
- OSV: https://osv.dev/vulnerability/CVE-2026-90443

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90443/
Summaries are generated and may contain mistakes; the official description above is the record.