# CVE-2026-63301: Denial of Service in Quick.CMS

> An attacker can cause a Denial of Service in Quick.CMS by deleting the primary language via an unprotected API endpoint, potentially exploiting a CSRF flaw.

- **Severity:** High 7.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Jul 2026
- **Updated:** 28 Jul 2026
- **Also known as:** GHSA-4pmv-mf66-4v3h

## What is CVE-2026-63301?

CVE-2026-63301 is a high-severity missing authorization vulnerability in OpenSolution Quick.CMS, published on 28 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

In Quick.CMS, the administrative user interface restricts deletion of the primary language by omitting the corresponding option from the interface; however, the underlying language-deletion API endpoint does not enforce an equivalent server-side authorization check. As a result, an authenticated administrator can bypass the UI-level restriction and delete the primary language by sending a direct HTTP request to the API endpoint. Successful deletion of the primary language results in a Denial of Service (DoS) of application.

Critically, when combined with a separate Cross-Site Request Forgery (CSRF) vulnerability (CVE-2026-1468) an unauthenticated remote attacker can craft a malicious link, which if visited by an authenticated administrator, will trigger the DoS condition without direct access to the application

The vendor assessed the likelihood of exploitation as very low and determined that a fix is not necessary.

Weakness: CWE-602 (Client-Side Enforcement of Server-Side Security)

## Which versions are affected by CVE-2026-63301?


## How do I fix CVE-2026-63301?

No fix has been published for CVE-2026-63301 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63301 being exploited?

There is no known exploitation of CVE-2026-63301 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63301 and fix it if it is affected.

What it is: CVE-2026-63301 is a high-severity missing authorization vulnerability in OpenSolution Quick.CMS, published on 28 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-63301 in the wild and no public exploit code.

Affected product: OpenSolution Quick.CMS. 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-2026-63301/ (Markdown: https://insights.sbomify.com/CVE-2026-63301/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63301
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63301
- OSV: https://osv.dev/vulnerability/CVE-2026-63301

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63301/
Summaries are generated and may contain mistakes; the official description above is the record.