CVE-2026-42504

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-03. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
43.2%
KEV
Not listed

Published

June 2, 2026

Last Modified

July 21, 2026

Advisory Details (4)

Auto-updated Jun 11, 2026
No patch confirmed yet.
generic

GO-2026-5038 - Go Packages

https://pkg.go.dev/vuln/GO-2026-5038
generic
https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw
generic

mime: quadratic complexity in WordDecoder.DecodeHeader · Issue #79217 · golang/go · GitHub

https://go.dev/issue/79217
generic
https://go.dev/cl/774481

Vendor Advisories for CVE-2026-42504(14)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatgolang1-25-main-1.25.11-2.hum12026-06-04redhat
redhatgolang1-26-main-1.26.4-2.hum12026-06-04redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.26.4—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 84× 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 169 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42504?
CVE-2026-42504 is a high vulnerability published on June 2, 2026. Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
When was CVE-2026-42504 disclosed?
CVE-2026-42504 was first published in the National Vulnerability Database on June 2, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42504 actively exploited?
CVE-2026-42504 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 43.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42504?
CVE-2026-42504 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42504?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42504, 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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