CVE-2026-42499

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-07. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
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

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

Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
52.1%
KEV
Not listed

Published

May 7, 2026

Last Modified

July 6, 2026

Advisory Details (4)

Auto-updated Jun 6, 2026
No patch confirmed yet.
generic

GO-2026-4977 - Go Packages

https://pkg.go.dev/vuln/GO-2026-4977
generic
https://groups.google.com/g/golang-announce/c/qcCIEXso47M
generic

net/mail: quadratic string concatenation in consumePhrase · Issue #78987 · golang/go · GitHub

https://go.dev/issue/78987
generic
https://go.dev/cl/771520

Vendor Advisories for CVE-2026-42499(8)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.26.3—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 0× in last 7d / 0× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 02:23 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-05 02:30 UTCEPSS rescore
  6. 2026-07-04 06:31 UTCEPSS rescore
  7. 2026-07-01 15:06 UTCEPSS rescore
  8. 2026-06-30 23:22 UTCEPSS rescore
  9. 2026-06-29 14:06 UTCEPSS rescore
  10. 2026-06-28 14:07 UTCEPSS rescore
  11. 2026-06-28 09:08 UTCEG score recompute
  12. 2026-06-28 09:08 UTCGHSA enrichment
  13. 2026-06-28 04:56 UTCEPSS rescore
  14. 2026-06-27 14:19 UTCEG score recompute
  15. 2026-06-27 14:19 UTCGHSA enrichment
  16. 2026-06-27 03:08 UTCEPSS rescore
  17. 2026-06-26 22:11 UTCEG score recompute
  18. 2026-06-26 22:11 UTCGHSA enrichment
  19. 2026-06-25 13:49 UTCEPSS rescore
  20. 2026-06-25 13:49 UTCEPSS rescore
  21. 2026-06-24 14:05 UTCEPSS rescore
  22. 2026-06-23 21:33 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
Show 75 more
  1. 2026-06-21 14:56 UTCEPSS rescore
  2. 2026-06-21 01:59 UTCEPSS rescore
  3. 2026-06-19 19:25 UTCEPSS rescore
  4. 2026-06-18 17:52 UTCEPSS rescore
  5. 2026-06-18 17:52 UTCEPSS rescore
  6. 2026-06-17 17:53 UTCEPSS rescore
  7. 2026-06-17 03:25 UTCEG score recompute
  8. 2026-06-17 03:25 UTCGHSA enrichment
  9. 2026-06-16 17:52 UTCEPSS rescore
  10. 2026-06-15 17:49 UTCEPSS rescore
  11. 2026-06-15 02:37 UTCEG score recompute
  12. 2026-06-15 02:37 UTCGHSA enrichment
  13. 2026-06-14 15:44 UTCEG score recompute
  14. 2026-06-14 15:43 UTCGHSA enrichment
  15. 2026-06-14 03:30 UTCEG score recompute
  16. 2026-06-14 03:30 UTCGHSA enrichment
  17. 2026-06-13 23:00 UTCEPSS rescore
  18. 2026-06-12 23:12 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-12 21:13 UTCEG score recompute
  21. 2026-06-12 21:13 UTCGHSA enrichment
  22. 2026-06-12 05:17 UTCEG score recompute
  23. 2026-06-12 05:17 UTCGHSA enrichment
  24. 2026-06-11 18:25 UTCEG score recompute
  25. 2026-06-11 18:25 UTCGHSA enrichment
  26. 2026-06-11 14:00 UTCEPSS rescore
  27. 2026-06-11 07:28 UTCEG score recompute
  28. 2026-06-11 07:28 UTCGHSA enrichment
  29. 2026-06-10 22:18 UTCEPSS rescore
  30. 2026-06-10 20:36 UTCEG score recompute
  31. 2026-06-10 20:36 UTCGHSA enrichment
  32. 2026-06-10 13:22 UTCEPSS rescore
  33. 2026-06-10 13:22 UTCEPSS rescore
  34. 2026-06-10 09:43 UTCEG score recompute
  35. 2026-06-10 09:43 UTCGHSA enrichment
  36. 2026-06-09 22:51 UTCEG score recompute
  37. 2026-06-09 22:51 UTCGHSA enrichment
  38. 2026-06-09 09:36 UTCEG score recompute
  39. 2026-06-09 09:36 UTCGHSA enrichment
  40. 2026-06-08 21:57 UTCEG score recompute
  41. 2026-06-08 21:57 UTCGHSA enrichment
  42. 2026-06-08 14:17 UTCEPSS rescore
  43. 2026-06-08 14:17 UTCEPSS rescore
  44. 2026-06-08 05:18 UTCEG score recompute
  45. 2026-06-08 05:18 UTCGHSA enrichment
  46. 2026-06-07 18:26 UTCEG score recompute
  47. 2026-06-07 18:26 UTCGHSA enrichment
  48. 2026-06-07 15:25 UTCEPSS rescore
  49. 2026-06-07 15:25 UTCEPSS rescore
  50. 2026-06-07 07:33 UTCEG score recompute
  51. 2026-06-07 07:33 UTCGHSA enrichment
  52. 2026-06-06 20:41 UTCEG score recompute
  53. 2026-06-06 20:41 UTCGHSA enrichment
  54. 2026-06-06 13:47 UTCEPSS rescore
  55. 2026-06-06 13:47 UTCEPSS rescore
  56. 2026-06-06 09:49 UTCEG score recompute
  57. 2026-06-06 09:49 UTCGHSA enrichment
  58. 2026-06-05 22:55 UTCEG score recompute
  59. 2026-06-05 22:55 UTCGHSA enrichment
  60. 2026-06-05 22:47 UTCEPSS rescore
  61. 2026-06-05 11:41 UTCEG score recompute
  62. 2026-06-05 11:41 UTCGHSA enrichment
  63. 2026-06-05 06:10 UTCEPSS rescore
  64. 2026-06-05 06:10 UTCEPSS rescore
  65. 2026-06-05 00:48 UTCEG score recompute
  66. 2026-06-05 00:48 UTCGHSA enrichment
  67. 2026-06-04 13:39 UTCEG score recompute
  68. 2026-06-04 13:39 UTCGHSA enrichment
  69. 2026-06-04 13:12 UTCEPSS rescore
  70. 2026-06-04 13:12 UTCEPSS rescore
  71. 2026-06-04 02:46 UTCEG score recompute
  72. 2026-06-04 02:46 UTCGHSA enrichment
  73. 2026-06-03 15:52 UTCEG score recompute
  74. 2026-06-03 15:52 UTCGHSA enrichment
  75. 2026-06-03 04:57 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-42499?
CVE-2026-42499 is a high vulnerability published on May 7, 2026. Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.
When was CVE-2026-42499 disclosed?
CVE-2026-42499 was first published in the National Vulnerability Database on May 7, 2026, with the most recent update on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42499 actively exploited?
CVE-2026-42499 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 52.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42499?
CVE-2026-42499 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42499?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42499, 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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