# CVE-2026-10099: XX-Net V5.16.6 WebSocket Frame Parsing Data Corruption via simple_http_server.py

> Attackers can corrupt application data by sending unmasked WebSocket frames due to improper parsing logic in XX-Net's HTTP server.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 May 2026
- **Updated:** 23 Jun 2026
- **Also known as:** GHSA-cwjv-w927-x7gr

## What is CVE-2026-10099?

CVE-2026-10099 is a medium-severity vulnerability in XX-Net, published on 29 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

XX-Net V5.16.6 contains a WebSocket frame parsing vulnerability in the WebSocket_receive_worker routine of simple_http_server.py that allows attackers to cause corrupted application data by sending unmasked WebSocket frames. The server unconditionally reads 4 bytes as a masking key regardless of whether the MASK bit is set in the frame header, causing the first 4 bytes of payload to be consumed as a mask key and the remaining payload to be incorrectly XOR-decoded, resulting in data corruption alongside missing RSV bit, opcode, and FIN fragmentation validations.

Weakness: CWE-1286 (Improper Validation of Syntactic Correctness of Input)

## Which versions are affected by CVE-2026-10099?


## How do I fix CVE-2026-10099?

No fix has been published for CVE-2026-10099 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10099 being exploited?

There is no known exploitation of CVE-2026-10099 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10099 and fix it if it is affected.

What it is: CVE-2026-10099 is a medium-severity vulnerability in XX-Net, published on 29 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-10099 in the wild and no public exploit code.

Affected product: XX-Net. 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-2026-10099/ (Markdown: https://insights.sbomify.com/CVE-2026-10099/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10099
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10099
- OSV: https://osv.dev/vulnerability/CVE-2026-10099

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10099/
Summaries are generated and may contain mistakes; the official description above is the record.