CVE-2026-27138

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

Score 5.9 from GitHub Security Advisory published 2026-03-07. NVD baseline CVSS 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

A fix is available — apply it.

Certificate verification can panic when a certificate in the chain has an empty DNS name and another certificate in the chain has excluded name constraints. This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

March 6, 2026

Last Modified

June 17, 2026

Advisory Details (4)

Auto-updated Aug 4, 2026
No patch confirmed yet.
generic

GO-2026-4600 - Go Packages

https://pkg.go.dev/vuln/GO-2026-4600
generic
https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk
generic

crypto/x509: panic in name constraint checking for malformed certificates (CVE-2026-27138) · Issue #77953 · golang/go · GitHub

https://go.dev/issue/77953
generic
https://go.dev/cl/752183

Vendor Advisories for CVE-2026-27138(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatgolang1-26-main-1.26.2-1.hum12026-04-09redhat

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

(2 across 2 ecosystems)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
golang-1.261.26.0-1, 1.26~rc2-1, 1.26~rc3-1, 1.26~rc3-21.26.1-1—
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.26.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 48× 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 198 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-27138?
CVE-2026-27138 is a medium vulnerability published on March 6, 2026. Certificate verification can panic when a certificate in the chain has an empty DNS name and another certificate in the chain has excluded name constraints. This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.
When was CVE-2026-27138 disclosed?
CVE-2026-27138 was first published in the National Vulnerability Database on March 6, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27138 actively exploited?
CVE-2026-27138 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 72.1% of all scored CVEs.
What is the CVSS score of CVE-2026-27138?
CVE-2026-27138 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-27138?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27138, 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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