# CVE-2026-18720: kalcaddle kodbox msgWarning Plugin action improper authorization

> Remote attackers can bypass authorization checks in the msgWarning plugin of kodbox to perform unauthorized actions.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-mv6j-rvc6-f296

## What is CVE-2026-18720?

CVE-2026-18720 is a medium-severity missing authorization vulnerability in kalcaddle kodbox, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw has been found in kalcaddle kodbox 1.67 Build 02. This vulnerability affects unknown code of the file /index.php?plugin/msgWarning/action of the component msgWarning Plugin. Executing a manipulation can lead to improper authorization. It is possible to launch the attack remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-285 (Improper Authorization), CWE-266 (Incorrect Privilege Assignment)

## Which versions are affected by CVE-2026-18720?


## How do I fix CVE-2026-18720?

No fix has been published for CVE-2026-18720 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18720 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18720 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18720 and fix it if it is affected.

What it is: CVE-2026-18720 is a medium-severity missing authorization vulnerability in kalcaddle kodbox, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18720 exists.

Affected product: kalcaddle kodbox. 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-2026-18720/ (Markdown: https://insights.sbomify.com/CVE-2026-18720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18720
- OSV: https://osv.dev/vulnerability/CVE-2026-18720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18720/
Summaries are generated and may contain mistakes; the official description above is the record.