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)
EG Risk
—
EPSS
53.2%
KEV
Not listed

Published

May 7, 2026

Last Modified

July 21, 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(20)

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.

All Vendor Advisories

(2)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 45× 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 145 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 09:53 UTCOSV refresh
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 02:00 UTCEPSS rescore
  12. 2026-07-13 22:30 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-13 06:13 UTCEPSS rescore
  15. 2026-07-12 05:46 UTCEPSS rescore
  16. 2026-07-11 08:27 UTCEPSS rescore
  17. 2026-07-09 19:10 UTCEPSS rescore
  18. 2026-07-08 15:15 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-06 16:27 UTCEPSS rescore
  22. 2026-07-06 02:23 UTCEPSS rescore
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-05 02:30 UTCEPSS rescore
  25. 2026-07-04 06:31 UTCEPSS rescore
Show 75 more
  1. 2026-07-01 15:06 UTCEPSS rescore
  2. 2026-06-30 23:22 UTCEPSS rescore
  3. 2026-06-29 14:06 UTCEPSS rescore
  4. 2026-06-29 14:06 UTCEPSS rescore
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 14:07 UTCEPSS rescore
  7. 2026-06-28 09:09 UTCVendor advisory
  8. 2026-06-28 09:09 UTCGHSA enrichment
  9. 2026-06-28 04:56 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 14:19 UTCVendor advisory
  12. 2026-06-27 14:19 UTCGHSA enrichment
  13. 2026-06-27 03:08 UTCEPSS rescore
  14. 2026-06-26 22:13 UTCVendor advisory
  15. 2026-06-26 22:13 UTCGHSA enrichment
  16. 2026-06-25 13:49 UTCEPSS rescore
  17. 2026-06-25 13:49 UTCEPSS rescore
  18. 2026-06-24 14:05 UTCEPSS rescore
  19. 2026-06-23 21:33 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-22 14:25 UTCEPSS rescore
  23. 2026-06-21 14:56 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 01:59 UTCEPSS rescore
  26. 2026-06-19 19:25 UTCEPSS rescore
  27. 2026-06-19 19:25 UTCEPSS rescore
  28. 2026-06-18 17:52 UTCEPSS rescore
  29. 2026-06-18 17:52 UTCEPSS rescore
  30. 2026-06-17 17:53 UTCEPSS rescore
  31. 2026-06-17 03:35 UTCVendor advisory
  32. 2026-06-17 03:34 UTCGHSA enrichment
  33. 2026-06-16 17:52 UTCEPSS rescore
  34. 2026-06-15 17:49 UTCEPSS rescore
  35. 2026-06-15 03:23 UTCVendor advisory
  36. 2026-06-15 03:22 UTCGHSA enrichment
  37. 2026-06-14 23:18 UTCEPSS rescore
  38. 2026-06-14 15:49 UTCVendor advisory
  39. 2026-06-14 15:49 UTCGHSA enrichment
  40. 2026-06-14 03:32 UTCVendor advisory
  41. 2026-06-14 03:32 UTCGHSA enrichment
  42. 2026-06-13 23:00 UTCEPSS rescore
  43. 2026-06-12 23:12 UTCEPSS rescore
  44. 2026-06-12 23:12 UTCEPSS rescore
  45. 2026-06-12 21:16 UTCVendor advisory
  46. 2026-06-12 21:15 UTCGHSA enrichment
  47. 2026-06-12 08:14 UTCVendor advisory
  48. 2026-06-12 08:14 UTCGHSA enrichment
  49. 2026-06-11 20:48 UTCVendor advisory
  50. 2026-06-11 20:48 UTCGHSA enrichment
  51. 2026-06-11 14:00 UTCEPSS rescore
  52. 2026-06-11 09:22 UTCVendor advisory
  53. 2026-06-11 09:22 UTCGHSA enrichment
  54. 2026-06-10 22:18 UTCEPSS rescore
  55. 2026-06-10 21:57 UTCVendor advisory
  56. 2026-06-10 21:57 UTCGHSA enrichment
  57. 2026-06-10 13:22 UTCEPSS rescore
  58. 2026-06-10 10:31 UTCVendor advisory
  59. 2026-06-10 10:31 UTCGHSA enrichment
  60. 2026-06-09 22:58 UTCVendor advisory
  61. 2026-06-09 22:58 UTCGHSA enrichment
  62. 2026-06-09 11:32 UTCVendor advisory
  63. 2026-06-09 11:32 UTCGHSA enrichment
  64. 2026-06-09 00:07 UTCVendor advisory
  65. 2026-06-09 00:07 UTCGHSA enrichment
  66. 2026-06-08 14:17 UTCEPSS rescore
  67. 2026-06-08 14:17 UTCEPSS rescore
  68. 2026-06-08 12:41 UTCGHSA enrichment
  69. 2026-06-08 01:15 UTCGHSA enrichment
  70. 2026-06-07 15:25 UTCEPSS rescore
  71. 2026-06-07 15:25 UTCEPSS rescore
  72. 2026-06-07 15:25 UTCEPSS rescore
  73. 2026-06-07 13:50 UTCGHSA enrichment
  74. 2026-06-07 02:24 UTCGHSA enrichment
  75. 2026-06-06 14:59 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 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33811 actively exploited?
CVE-2026-33811 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 53.2% 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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