CVE-2026-42545

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 87% 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
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.9Exploit: 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 0.2.0 to 2.7.4, Granian aborts a worker process if a WSGI application returns an invalid HTTP response header name or value. The WSGI response conversion path uses .unwrap() on both the header name and header value constructors, so malformed output from the application becomes a process abort instead of a handled error. This vulnerability is fixed in 2.7.4.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
12.9%
KEV
Not listed

Published

May 12, 2026

Last Modified

May 14, 2026

Advisory Details (1)

Auto-updated May 14, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

DoS via WSGI response header panic · Advisory · emmett-framework/granian · GitHub

https://github.com/emmett-framework/granian/security/advisories/GHSA-f5p7-9fr5-8jmj

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
granian0.2.6 ... 2.7.3 (66 versions)2.7.4—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 33× 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.

  1. 2026-07-23 03:11 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 23:23 UTCOSV refresh
  10. 2026-07-15 16:57 UTCEPSS rescore
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  12. 2026-07-13 06:13 UTCEPSS rescore
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  15. 2026-07-09 19:10 UTCEPSS rescore
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  17. 2026-07-07 13:46 UTCEPSS rescore
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  25. 2026-06-30 23:22 UTCEPSS rescore
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  1. 2026-06-29 14:06 UTCEPSS rescore
  2. 2026-06-28 14:07 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-27 03:08 UTCEPSS rescore
  5. 2026-06-25 13:49 UTCEPSS rescore
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  7. 2026-06-24 14:05 UTCEPSS rescore
  8. 2026-06-23 21:33 UTCEPSS rescore
  9. 2026-06-22 14:25 UTCEPSS rescore
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  11. 2026-06-21 14:56 UTCEPSS rescore
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  13. 2026-06-21 01:59 UTCEPSS rescore
  14. 2026-06-19 19:25 UTCEPSS rescore
  15. 2026-06-17 17:53 UTCEPSS rescore
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  17. 2026-06-15 17:49 UTCEPSS rescore
  18. 2026-06-13 23:00 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-12 23:12 UTCEPSS rescore
  21. 2026-06-11 14:00 UTCEPSS rescore
  22. 2026-06-10 22:18 UTCEPSS rescore
  23. 2026-06-10 13:22 UTCEPSS rescore
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  25. 2026-06-08 14:17 UTCEPSS rescore
  26. 2026-06-08 14:17 UTCEPSS rescore
  27. 2026-06-07 15:25 UTCEPSS rescore
  28. 2026-06-07 15:25 UTCEPSS rescore
  29. 2026-06-06 13:47 UTCEPSS rescore
  30. 2026-06-06 13:47 UTCEPSS rescore
  31. 2026-06-05 22:47 UTCEPSS rescore
  32. 2026-06-05 06:10 UTCEPSS rescore
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  34. 2026-06-04 13:12 UTCEPSS rescore
  35. 2026-06-04 13:12 UTCEPSS rescore
  36. 2026-06-02 20:13 UTCEPSS rescore
  37. 2026-06-01 13:52 UTCEPSS rescore
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  39. 2026-05-31 22:30 UTCEPSS rescore
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  41. 2026-05-31 00:16 UTCEPSS rescore
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  43. 2026-05-29 13:44 UTCEPSS rescore
  44. 2026-05-29 13:44 UTCEPSS rescore
  45. 2026-05-28 13:44 UTCEPSS rescore
  46. 2026-05-28 13:44 UTCEPSS rescore
  47. 2026-05-27 13:40 UTCEPSS rescore
  48. 2026-05-27 13:40 UTCEPSS rescore
  49. 2026-05-26 13:44 UTCEPSS rescore
  50. 2026-05-26 07:18 UTCEPSS rescore
  51. 2026-05-26 07:18 UTCEPSS rescore
  52. 2026-05-20 22:38 UTCEPSS rescore
  53. 2026-05-20 22:38 UTCEPSS rescore
  54. 2026-05-20 12:41 UTCEG score recompute
  55. 2026-05-20 11:22 UTCEPSS rescore
  56. 2026-05-20 11:22 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-42545?
CVE-2026-42545 is a medium vulnerability published on May 12, 2026. Granian is a Rust HTTP server for Python applications. From 0.2.0 to 2.7.4, Granian aborts a worker process if a WSGI application returns an invalid HTTP response header name or value. The WSGI response conversion path uses .unwrap() on both the header name and header value constructors, so…
When was CVE-2026-42545 disclosed?
CVE-2026-42545 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42545 actively exploited?
CVE-2026-42545 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42545?
CVE-2026-42545 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-42545?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42545, 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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