CVE-2026-59851

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-21. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

July 21, 2026

Last Modified

August 17, 2026

Advisory Details (2)

Auto-updated Jul 21, 2026
Patch available. Sources: redhat.
redhat

2498184 – (CVE-2026-59851) CVE-2026-59851 libssh: libssh: authentication bypass via missing GSSAPI principal check

https://bugzilla.redhat.com/show_bug.cgi?id=2498184
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-59851

Vendor Advisories for CVE-2026-59851(3)

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
redhatlibssh-0:0.12.0-3.el10_22026-08-17redhat
redhatlibssh-main-0.12.1-4.hum12026-07-21redhat

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)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libssh0.11.2-1, 0.11.3-1, 0.12.0-1, 0.12.0-2, 0.12.0-30.12.1-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 127× 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 248 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-59851?
CVE-2026-59851 is a high vulnerability published on July 21, 2026. A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users.
When was CVE-2026-59851 disclosed?
CVE-2026-59851 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59851 actively exploited?
CVE-2026-59851 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 78.6% of all scored CVEs.
What is the CVSS score of CVE-2026-59851?
CVE-2026-59851 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-59851?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59851, 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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