CVE-2026-42544

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

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

Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whose Sec-WebSocket-Protocol header contains non-ASCII bytes. The crash happens in Granian's WebSocket scope construction path, before the ASGI application is invoked. This vulnerability is fixed in 2.7.4.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
24.3%
KEV
Not listed

Published

May 12, 2026

Last Modified

May 18, 2026

Advisory Details (1)

Auto-updated May 12, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Unauthenticated DoS via WebSocket subprotocol header panic · Advisory · emmett-framework/granian · GitHub

https://github.com/emmett-framework/granian/security/advisories/GHSA-vrg7-482j-p6f6

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
granian1.2.3 ... 2.7.3 (58 versions)2.7.4—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 48× 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 106 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-42544?
CVE-2026-42544 is a high vulnerability published on May 12, 2026. Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whose Sec-WebSocket-Protocol header contains non-ASCII bytes. The crash happens in Granian's WebSocket scope construction…
When was CVE-2026-42544 disclosed?
CVE-2026-42544 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42544 actively exploited?
CVE-2026-42544 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42544?
CVE-2026-42544 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-42544?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42544, 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.

Dependency Blast Radius

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