CVE-2026-39830

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cisa-adp, epss
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
41.7%
KEV
Not listed

Published

May 22, 2026

Last Modified

July 21, 2026

Advisory Details (5)

Auto-updated Jun 1, 2026
No patch confirmed yet.
generic

GO-2026-5017 - Go Packages

https://pkg.go.dev/vuln/GO-2026-5017
generic
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
generic

x/crypto/ssh: client can cause server deadlock on unexpected responses · Issue #79564 · golang/go · GitHub

https://go.dev/issue/79564
generic
https://go.dev/cl/781664
generic
https://go.dev/cl/781640

Vendor Advisories for CVE-2026-39830(20)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulxd-tools (2.0.11-0ubuntu1~16.04.4+esm3) @ xenial2026-06-29ubuntu
ubuntugoogle-guest-agent (20250116.00-0ubuntu1~22.04.3) @ jammy2026-06-29ubuntu
redhatbuildah-2:1.43.1-2.el9_82026-06-25redhat

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
golang.org/x/crypto—0.52.0—

Weakness Classification(2)

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

All Vendor Advisories

(4)

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 / 50× 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 187 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. 2026-07-17 23:29 UTCOSV refresh
  8. 2026-07-16 17:03 UTCEPSS rescore
  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 20:53 UTCVendor advisory
  4. 2026-06-29 16:40 UTCVendor advisory
  5. 2026-06-29 14:06 UTCEPSS rescore
  6. 2026-06-28 14:07 UTCEPSS rescore
  7. 2026-06-28 12:30 UTCVendor advisory
  8. 2026-06-28 07:57 UTCVendor advisory
  9. 2026-06-28 04:56 UTCEPSS rescore
  10. 2026-06-28 03:50 UTCVendor advisory
  11. 2026-06-27 23:42 UTCVendor advisory
  12. 2026-06-27 19:32 UTCVendor advisory
  13. 2026-06-27 11:51 UTCVendor advisory
  14. 2026-06-27 07:21 UTCVendor advisory
  15. 2026-06-27 03:08 UTCEPSS rescore
  16. 2026-06-26 23:23 UTCVendor advisory
  17. 2026-06-26 19:15 UTCVendor advisory
  18. 2026-06-26 03:24 UTCVendor advisory
  19. 2026-06-25 23:16 UTCVendor advisory
  20. 2026-06-25 18:21 UTCVendor advisory
  21. 2026-06-25 14:10 UTCVendor advisory
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-25 13:49 UTCEPSS rescore
  24. 2026-06-24 14:05 UTCEPSS rescore
  25. 2026-06-23 21:33 UTCEPSS rescore
  26. 2026-06-22 14:25 UTCEPSS rescore
  27. 2026-06-22 14:25 UTCEPSS rescore
  28. 2026-06-21 14:56 UTCEPSS rescore
  29. 2026-06-21 14:56 UTCEPSS rescore
  30. 2026-06-21 01:59 UTCEPSS rescore
  31. 2026-06-19 19:25 UTCEPSS rescore
  32. 2026-06-18 17:52 UTCEPSS rescore
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-17 19:56 UTCVendor advisory
  35. 2026-06-17 17:53 UTCEPSS rescore
  36. 2026-06-16 19:29 UTCVendor advisory
  37. 2026-06-16 17:52 UTCEPSS rescore
  38. 2026-06-16 11:08 UTCVendor advisory
  39. 2026-06-16 07:01 UTCVendor advisory
  40. 2026-06-16 02:53 UTCVendor advisory
  41. 2026-06-15 22:46 UTCVendor advisory
  42. 2026-06-15 17:49 UTCEPSS rescore
  43. 2026-06-15 15:00 UTCVendor advisory
  44. 2026-06-15 07:50 UTCVendor advisory
  45. 2026-06-15 02:54 UTCVendor advisory
  46. 2026-06-14 23:18 UTCEPSS rescore
  47. 2026-06-14 22:46 UTCVendor advisory
  48. 2026-06-14 18:39 UTCVendor advisory
  49. 2026-06-14 14:31 UTCVendor advisory
  50. 2026-06-14 10:23 UTCVendor advisory
  51. 2026-06-14 06:15 UTCVendor advisory
  52. 2026-06-14 02:03 UTCVendor advisory
  53. 2026-06-13 23:00 UTCEPSS rescore
  54. 2026-06-13 11:01 UTCVendor advisory
  55. 2026-06-13 06:45 UTCVendor advisory
  56. 2026-06-13 02:37 UTCVendor advisory
  57. 2026-06-12 23:12 UTCEPSS rescore
  58. 2026-06-12 23:12 UTCEPSS rescore
  59. 2026-06-12 22:28 UTCVendor advisory
  60. 2026-06-12 18:21 UTCVendor advisory
  61. 2026-06-12 14:08 UTCVendor advisory
  62. 2026-06-12 10:00 UTCVendor advisory
  63. 2026-06-12 01:44 UTCVendor advisory
  64. 2026-06-11 17:29 UTCVendor advisory
  65. 2026-06-11 14:00 UTCEPSS rescore
  66. 2026-06-11 13:22 UTCVendor advisory
  67. 2026-06-11 09:14 UTCVendor advisory
  68. 2026-06-11 05:06 UTCVendor advisory
  69. 2026-06-11 00:58 UTCVendor advisory
  70. 2026-06-10 22:18 UTCEPSS rescore
  71. 2026-06-10 20:51 UTCVendor advisory
  72. 2026-06-10 16:44 UTCVendor advisory
  73. 2026-06-10 13:22 UTCEPSS rescore
  74. 2026-06-10 12:37 UTCVendor advisory
  75. 2026-06-10 08:30 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-39830?
CVE-2026-39830 is a critical vulnerability published on May 22, 2026. A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
When was CVE-2026-39830 disclosed?
CVE-2026-39830 was first published in the National Vulnerability Database on May 22, 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-2026-39830 actively exploited?
CVE-2026-39830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-39830?
CVE-2026-39830 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-39830?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39830, 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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