# CVE-2026-10099

## Summary

- **CVE ID:** CVE-2026-10099
- **Severity:** MEDIUM
- **CVSS Score:** 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)
- **CWE:** CWE-1286
- **Published:** May 29, 2026
- **Last Modified:** Jun 23, 2026

## 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.

## Affected Products

- XX-net — XX-Net (0)

## References

- [CNA](https://github.com/XX-net/XX-Net/issues/14169)
- [CNA](https://github.com/XX-net/XX-Net/pull/14170)
- [CNA](https://github.com/XX-net/XX-Net/commit/a68b972a84ed6e52df9f30237cf47493b9231b53)
- [CNA](https://www.vulncheck.com/advisories/xx-net-websocket-frame-parsing-data-corruption-via-simple-http-server-py)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 2.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._