CVE-2026-10099 json
XX-Net V5.16.6 WebSocket Frame Parsing Data Corruption via simple_http_server.py
published 5mo ago modified yesterday also EUVD-2026-33346
- cvss
- 4.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 2%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- github.com/XX-net/XX-Net@a68b972 commit
- github.com/XX-net/XX-Net#14170 pull request
Is CVE-2026-10099 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.0 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| CNA | 4.0 | 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 |
| CNA | 4.0 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- XX-net XX-Net
Classification
- Weakness
-
- CWE-1286 Improper Validation of Syntactic Correctness of Input
References
-
github.com
/XX-net/XX-Net/pull/14170
issue-tracking, patch
-
github.com
/XX-net/XX-Net/commit/a68b972a84ed6e52df9f30237cf47493b9231b53
patch
-
github.com
/XX-net/XX-Net/issues/14169
issue-tracking
-
vulncheck.com
/advisories/xx-net-websocket-frame-parsing-data-corruption-via-simple-http-server-py
third-party-advisory
Sources
- CVE List CVE-2026-10099
- NVD CVE-2026-10099
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.