CVE-2026-10099

MEDIUMPre-NVD 4.04.0—
EchelonGraph scoreMEDIUM confidence

Score 4.0 from GitHub Security Advisory published 2026-05-29. the CNA's CVSS baseline 4.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
4.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.0Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
4.0
EG Score
4.0(medium)
EPSS
2.6%
KEV
Not listed

Published

May 29, 2026

Last Modified

June 23, 2026

Advisory Details (4)

Auto-updated Jun 18, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

XX-Net V5.16.6 WebSocket Frame Parsing Data Corruption via simple_http_server.py | Advisories | VulnCheck

https://www.vulncheck.com/advisories/xx-net-websocket-frame-parsing-data-corruption-via-simple-http-server-py
github_pr

fix: check WebSocket MASK bit before reading masking key (RFC 6455 §5.2)

Fix merged in XX-net/XX-Net PR #14170 on 2026-05-12 — awaiting tagged release

https://github.com/XX-net/XX-Net/pull/14170
generic

WebSocket parser ignores MASK bit, always reads 4-byte masking key · Issue #14169 · XX-net/XX-Net · GitHub

https://github.com/XX-net/XX-Net/issues/14169
github_commit

commit a68b972a84ed (XX-net/XX-Net)

Fix landed in XX-net/XX-Net commit a68b972a84ed — awaiting tagged release

https://github.com/XX-net/XX-Net/commit/a68b972a84ed6e52df9f30237cf47493b9231b53

Vendor Advisories for CVE-2026-10099(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 62× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 128 total refreshes for this CVE.

  1. 2026-07-16 01:59 UTCEG score recompute
  2. 2026-07-16 01:59 UTCGHSA enrichment
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-14 14:08 UTCEG score recompute
  6. 2026-07-14 14:08 UTCGHSA enrichment
  7. 2026-07-13 22:30 UTCEPSS rescore
  8. 2026-07-13 06:12 UTCEPSS rescore
  9. 2026-07-12 05:46 UTCEPSS rescore
  10. 2026-07-11 17:34 UTCEG score recompute
  11. 2026-07-11 17:34 UTCGHSA enrichment
  12. 2026-07-11 08:27 UTCEPSS rescore
  13. 2026-07-09 19:10 UTCEPSS rescore
  14. 2026-07-08 17:25 UTCEG score recompute
  15. 2026-07-08 17:25 UTCGHSA enrichment
  16. 2026-07-08 15:15 UTCEPSS rescore
  17. 2026-07-08 15:15 UTCEPSS rescore
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 02:23 UTCEPSS rescore
  21. 2026-07-05 02:30 UTCEPSS rescore
  22. 2026-07-05 02:30 UTCEPSS rescore
  23. 2026-07-02 04:26 UTCEG score recompute
  24. 2026-07-02 04:26 UTCGHSA enrichment
  25. 2026-07-01 15:06 UTCEPSS rescore
Show 75 more
  1. 2026-07-01 15:06 UTCEPSS rescore
  2. 2026-07-01 01:33 UTCEG score recompute
  3. 2026-07-01 01:33 UTCGHSA enrichment
  4. 2026-06-29 14:06 UTCEPSS rescore
  5. 2026-06-29 12:56 UTCEG score recompute
  6. 2026-06-29 12:56 UTCGHSA enrichment
  7. 2026-06-28 14:07 UTCEPSS rescore
  8. 2026-06-28 13:48 UTCEG score recompute
  9. 2026-06-28 13:48 UTCGHSA enrichment
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-28 04:56 UTCEPSS rescore
  12. 2026-06-27 15:01 UTCEG score recompute
  13. 2026-06-27 15:01 UTCGHSA enrichment
  14. 2026-06-27 03:08 UTCEPSS rescore
  15. 2026-06-26 16:18 UTCEG score recompute
  16. 2026-06-26 16:18 UTCGHSA enrichment
  17. 2026-06-25 14:08 UTCEG score recompute
  18. 2026-06-25 14:08 UTCGHSA enrichment
  19. 2026-06-25 13:49 UTCEPSS rescore
  20. 2026-06-24 15:25 UTCEG score recompute
  21. 2026-06-24 15:25 UTCGHSA enrichment
  22. 2026-06-24 14:05 UTCEPSS rescore
  23. 2026-06-23 21:32 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-22 14:25 UTCEPSS rescore
  26. 2026-06-21 14:56 UTCEPSS rescore
  27. 2026-06-21 14:56 UTCEPSS rescore
  28. 2026-06-21 01:59 UTCEPSS rescore
  29. 2026-06-21 01:59 UTCEPSS rescore
  30. 2026-06-19 19:25 UTCEPSS rescore
  31. 2026-06-18 17:52 UTCEPSS rescore
  32. 2026-06-18 02:04 UTCEG score recompute
  33. 2026-06-18 02:04 UTCGHSA enrichment
  34. 2026-06-17 17:53 UTCEPSS rescore
  35. 2026-06-17 03:20 UTCEG score recompute
  36. 2026-06-17 03:20 UTCGHSA enrichment
  37. 2026-06-16 17:52 UTCEPSS rescore
  38. 2026-06-16 04:37 UTCEG score recompute
  39. 2026-06-16 04:37 UTCGHSA enrichment
  40. 2026-06-15 17:48 UTCEPSS rescore
  41. 2026-06-15 05:37 UTCEG score recompute
  42. 2026-06-15 05:37 UTCGHSA enrichment
  43. 2026-06-14 23:18 UTCEPSS rescore
  44. 2026-06-14 06:53 UTCEG score recompute
  45. 2026-06-14 06:53 UTCGHSA enrichment
  46. 2026-06-13 23:00 UTCEPSS rescore
  47. 2026-06-13 23:00 UTCEPSS rescore
  48. 2026-06-13 08:08 UTCEG score recompute
  49. 2026-06-13 08:08 UTCGHSA enrichment
  50. 2026-06-12 23:12 UTCEPSS rescore
  51. 2026-06-12 09:24 UTCEG score recompute
  52. 2026-06-12 09:24 UTCGHSA enrichment
  53. 2026-06-11 14:00 UTCEPSS rescore
  54. 2026-06-11 10:41 UTCEG score recompute
  55. 2026-06-11 10:41 UTCGHSA enrichment
  56. 2026-06-10 22:18 UTCEPSS rescore
  57. 2026-06-10 13:22 UTCEPSS rescore
  58. 2026-06-10 11:58 UTCEG score recompute
  59. 2026-06-10 11:58 UTCGHSA enrichment
  60. 2026-06-09 13:15 UTCEG score recompute
  61. 2026-06-09 13:15 UTCGHSA enrichment
  62. 2026-06-08 14:32 UTCEG score recompute
  63. 2026-06-08 14:32 UTCGHSA enrichment
  64. 2026-06-08 14:17 UTCEPSS rescore
  65. 2026-06-08 14:17 UTCEPSS rescore
  66. 2026-06-07 15:49 UTCEG score recompute
  67. 2026-06-07 15:49 UTCGHSA enrichment
  68. 2026-06-07 15:25 UTCEPSS rescore
  69. 2026-06-07 15:24 UTCEPSS rescore
  70. 2026-06-06 17:06 UTCEG score recompute
  71. 2026-06-06 17:06 UTCGHSA enrichment
  72. 2026-06-06 13:47 UTCEPSS rescore
  73. 2026-06-06 13:47 UTCEPSS rescore
  74. 2026-06-06 13:47 UTCEPSS rescore
  75. 2026-06-05 22:47 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-10099?
CVE-2026-10099 is a medium vulnerability published on May 29, 2026. XX-Net V5.16.6 contains a WebSocket frame parsing vulnerability in the WebSocketreceiveworker routine of simplehttpserver.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…
When was CVE-2026-10099 disclosed?
CVE-2026-10099 was first published in the National Vulnerability Database on May 29, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-10099 actively exploited?
CVE-2026-10099 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-10099?
CVE-2026-10099 has a CVSS v4.0 base score of 4.0 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-10099?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-10099, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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