CVE-2026-58051

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-28. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

June 28, 2026

Last Modified

June 30, 2026

Advisory Details (3)

Auto-updated Jun 28, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

libssh2 - Free of Uninitialized Pointer in publickey List Cleanup | Advisories | VulnCheck

https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup
generic

libssh2/src/publickey.c at master · libssh2/libssh2 · GitHub

https://github.com/libssh2/libssh2/blob/master/src/publickey.c
generic

exploitarium/libssh2-publickey-list-calc-poc at main · bikini/exploitarium · GitHub

https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc

Vendor Advisories for CVE-2026-58051(3)

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
ubuntulibssh2-1t64 (1.11.1-1ubuntu0.26.04.3) @ resolute2026-07-26ubuntu

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.

Weakness Classification(1)

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

All Vendor Advisories

(1)

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 18× in last 7d / 71× 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.

  1. 2026-07-27 16:58 UTCEG score recompute
  2. 2026-07-27 16:58 UTCGHSA enrichment
  3. 2026-07-27 14:14 UTCEPSS rescore
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-26 14:54 UTCEPSS rescore
  6. 2026-07-26 14:25 UTCEG score recompute
  7. 2026-07-26 14:25 UTCVendor advisory
  8. 2026-07-26 14:25 UTCGHSA enrichment
  9. 2026-07-25 14:18 UTCEPSS rescore
  10. 2026-07-25 14:18 UTCEPSS rescore
  11. 2026-07-24 14:18 UTCEPSS rescore
  12. 2026-07-24 14:18 UTCEPSS rescore
  13. 2026-07-23 14:18 UTCEPSS rescore
  14. 2026-07-23 14:18 UTCEPSS rescore
  15. 2026-07-23 03:20 UTCEG score recompute
  16. 2026-07-22 14:08 UTCEPSS rescore
  17. 2026-07-22 14:08 UTCEPSS rescore
  18. 2026-07-21 15:25 UTCEPSS rescore
  19. 2026-07-20 17:08 UTCEPSS rescore
  20. 2026-07-19 14:31 UTCEPSS rescore
  21. 2026-07-19 14:31 UTCEPSS rescore
  22. 2026-07-19 02:29 UTCEPSS rescore
  23. 2026-07-18 10:04 UTCEPSS rescore
  24. 2026-07-16 17:03 UTCEPSS rescore
  25. 2026-07-16 07:27 UTCVendor advisory
Show 48 more
  1. 2026-07-16 07:27 UTCGHSA enrichment
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 07:12 UTCGHSA enrichment
  5. 2026-07-15 02:00 UTCEPSS rescore
  6. 2026-07-15 02:00 UTCEPSS rescore
  7. 2026-07-14 06:56 UTCGHSA enrichment
  8. 2026-07-13 22:31 UTCEPSS rescore
  9. 2026-07-13 06:41 UTCGHSA enrichment
  10. 2026-07-13 06:13 UTCEPSS rescore
  11. 2026-07-13 06:13 UTCEPSS rescore
  12. 2026-07-12 06:22 UTCGHSA enrichment
  13. 2026-07-12 05:46 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-11 08:27 UTCEPSS rescore
  16. 2026-07-11 05:52 UTCGHSA enrichment
  17. 2026-07-10 05:37 UTCGHSA enrichment
  18. 2026-07-09 19:10 UTCEPSS rescore
  19. 2026-07-09 19:10 UTCEPSS rescore
  20. 2026-07-09 05:20 UTCGHSA enrichment
  21. 2026-07-08 15:16 UTCEPSS rescore
  22. 2026-07-08 15:16 UTCEPSS rescore
  23. 2026-07-08 05:04 UTCGHSA enrichment
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-07 13:46 UTCEPSS rescore
  26. 2026-07-07 04:47 UTCGHSA enrichment
  27. 2026-07-06 16:27 UTCEPSS rescore
  28. 2026-07-06 16:27 UTCEPSS rescore
  29. 2026-07-06 04:32 UTCGHSA enrichment
  30. 2026-07-06 02:23 UTCEPSS rescore
  31. 2026-07-06 02:23 UTCEPSS rescore
  32. 2026-07-05 04:15 UTCGHSA enrichment
  33. 2026-07-05 02:31 UTCEPSS rescore
  34. 2026-07-05 02:30 UTCEPSS rescore
  35. 2026-07-04 06:31 UTCEPSS rescore
  36. 2026-07-04 06:31 UTCEPSS rescore
  37. 2026-07-04 03:55 UTCGHSA enrichment
  38. 2026-07-03 03:24 UTCGHSA enrichment
  39. 2026-07-02 03:09 UTCGHSA enrichment
  40. 2026-07-01 15:07 UTCEPSS rescore
  41. 2026-07-01 02:55 UTCGHSA enrichment
  42. 2026-06-30 23:22 UTCEPSS rescore
  43. 2026-06-30 02:40 UTCGHSA enrichment
  44. 2026-06-29 14:06 UTCEPSS rescore
  45. 2026-06-29 02:25 UTCGHSA enrichment
  46. 2026-06-28 14:07 UTCEPSS rescore
  47. 2026-06-28 02:10 UTCEG score recompute
  48. 2026-06-28 02:09 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-58051?
CVE-2026-58051 is a medium vulnerability published on June 28, 2026. libssh2 through 1.11.1 grows its publickey list with SSH2REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2publickeylistfree operating on an uninitialized entry. A malicious SSH server offering the publickey…
When was CVE-2026-58051 disclosed?
CVE-2026-58051 was first published in the National Vulnerability Database on June 28, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-58051 actively exploited?
CVE-2026-58051 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 80.1% of all scored CVEs.
What is the CVSS score of CVE-2026-58051?
CVE-2026-58051 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-58051?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58051, 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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