# CVE-2026-18644: danpros HTMLy Delete Username Endpoint htmly.php unlink path traversal

> Remote attackers can exploit a path traversal vulnerability in the Delete Username Endpoint to delete arbitrary files via the unlink function.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **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:** 3 Aug 2026
- **Updated:** 3 Aug 2026
- **Also known as:** GHSA-g2qx-6r2x-hr8v

## What is CVE-2026-18644?

CVE-2026-18644 is a medium-severity path traversal vulnerability in danpros HTMLy, published on 3 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was identified in danpros HTMLy up to 3.1.1. Affected by this issue is the function unlink of the file /system/htmly.php of the component Delete Username Endpoint. Such manipulation of the argument File leads to path traversal. The attack can be launched remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-18644?


## How do I fix CVE-2026-18644?

No fix has been published for CVE-2026-18644 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18644 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18644 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18644 and fix it if it is affected.

What it is: CVE-2026-18644 is a medium-severity path traversal vulnerability in danpros HTMLy, published on 3 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18644 exists.

Affected product: danpros HTMLy. 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-2026-18644/ (Markdown: https://insights.sbomify.com/CVE-2026-18644/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18644
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18644
- OSV: https://osv.dev/vulnerability/CVE-2026-18644

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18644/
Summaries are generated and may contain mistakes; the official description above is the record.