CVE-2026-10099: XX-Net · Improper Validation of Syntactic Correctness of Input
Affects XX-NetSource CVE Database V5
Not known to be exploited · CVSS 4.0 Medium.
Data as of 8 Nov 2026, 14:20 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 3.1 | 4.0 |
|---|---|---|
| CNA (VulnCheck) | CVSS 4.0 | 5.1 |
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-06-01.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 29 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| XX-netXX-Net | Affected
| Fixed in– |
AI-suggested
Users should monitor vendor advisories for updates. Until a fix is available, cautious use of the affected versions is advised. There are no vendor advisories indicating that the issue is already mitigated or requires no action.
Description
XX-Net version 5.16.6 and earlier contain a vulnerability in the WebSocket frame parsing logic within simple_http_server.py. The server incorrectly processes unmasked WebSocket frames by always reading 4 bytes as a masking key regardless of the MASK bit, leading to corrupted application data. This flaw causes improper XOR decoding of the payload and lacks validation of RSV bits, opcode, and FIN fragmentation flags.
References
- github.com/XX-net/XX-Net/issues/14169 (opens in a new tab)
- github.com/XX-net/XX-Net/pull/14170 (opens in a new tab)
- github.com/XX-net/XX-Net/commit/a68b972a84ed6e52df9f30237cf47493b9231b53 (opens in a new tab)
- vulncheck.com/advisories/xx-net-websocket-frame-parsing-data-corruption-via-simple-http-server-py (opens in a new tab)