# CVE-2026-63303: Path Traversal in Quick.CMS

> An authenticated admin can read files outside the webroot via path traversal in Quick.CMS, though the vendor deems exploitation unlikely.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:L/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-5wcv-j62r-8fp5

## What is CVE-2026-63303?

CVE-2026-63303 is a medium-severity path traversal 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

A Path Traversal vulnerability exists in Quick.CMS through the URI path component of HTTP requests, where the server fails to normalize dot-dot-slash (../) sequences before resolving and serving the requested file. An authenticated attacker with admin privileges can use this vulnerability to read contents of files located in the sibling directory of the webroot via a crafted HTTP request containing ../ sequences in the URI.

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

Weakness: CWE-23 (Relative Path Traversal)

## Which versions are affected by CVE-2026-63303?


## How do I fix CVE-2026-63303?

No fix has been published for CVE-2026-63303 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63303 being exploited?

There is no known exploitation of CVE-2026-63303 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63303 and fix it if it is affected.

What it is: CVE-2026-63303 is a medium-severity path traversal 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-2026-63303 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-2026-63303/ (Markdown: https://insights.sbomify.com/CVE-2026-63303/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63303
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63303
- OSV: https://osv.dev/vulnerability/CVE-2026-63303

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63303/
Summaries are generated and may contain mistakes; the official description above is the record.