# CVE-2025-13826: Incorrect input validation on the Zervit portable HTTP/Web server

> Remote attackers can cause a denial of service in Zervit's portable HTTP server by sending malicious configuration reset requests due to poor input validation.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:U/V:D/RE:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Apr 2026
- **Updated:** 21 Apr 2026
- **Also known as:** GHSA-mwv3-mcxm-vh5m

## What is CVE-2025-13826?

CVE-2025-13826 is a high-severity denial of service vulnerability in Zervit portable HTTP/Web server, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Zervit's portable HTTP/web server is vulnerable to remote DoS attacks when a configuration reset request is made. The vulnerability is caused by inadequate validation of user-supplied input. An attacker can exploit this vulnerability by sending malicious requests. If the vulnerability is successfully exploited, the application can be made to stop responding, resulting in a DoS condition. It is possible to manually restart the application.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2025-13826?


## How do I fix CVE-2025-13826?

No fix has been published for CVE-2025-13826 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-13826 being exploited?

There is no known exploitation of CVE-2025-13826 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-13826 and fix it if it is affected.

What it is: CVE-2025-13826 is a high-severity denial of service vulnerability in Zervit portable HTTP/Web server, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-13826 in the wild and no public exploit code.

Affected product: Zervit portable HTTP/Web server. 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-2025-13826/ (Markdown: https://insights.sbomify.com/CVE-2025-13826/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-13826
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-13826
- OSV: https://osv.dev/vulnerability/CVE-2025-13826

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-13826/
Summaries are generated and may contain mistakes; the official description above is the record.