CVE-2026-33811

HIGHNVD 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

A fix is available — apply it.

When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
52.6%
KEV
Not listed

Published

May 7, 2026

Last Modified

July 6, 2026

Advisory Details (4)

Auto-updated May 12, 2026
No patch confirmed yet.
generic

GO-2026-4981 - Go Packages

https://pkg.go.dev/vuln/GO-2026-4981
generic
https://groups.google.com/g/golang-announce/c/qcCIEXso47M
generic

net: double-free of cgo pointer when handling long CNAME response · Issue #78803 · golang/go · GitHub

https://go.dev/issue/78803
generic
https://go.dev/cl/767860

Vendor Advisories for CVE-2026-33811(13)

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—1.26.3—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 98× 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 158 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-33811?
CVE-2026-33811 is a high vulnerability published on May 7, 2026. When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
When was CVE-2026-33811 disclosed?
CVE-2026-33811 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-2026-33811 actively exploited?
CVE-2026-33811 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 52.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-33811?
CVE-2026-33811 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-33811?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33811, 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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