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 — 3 sources updated this weekElevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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)
EPSS
19.9%
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(2)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 32× 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. 2026-07-07 04:47 UTCEG score recompute
  2. 2026-07-07 04:47 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 04:33 UTCEG score recompute
  6. 2026-07-06 04:32 UTCGHSA enrichment
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-05 04:16 UTCEG score recompute
  10. 2026-07-05 04:15 UTCGHSA enrichment
  11. 2026-07-05 02:31 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-04 03:55 UTCEG score recompute
  16. 2026-07-04 03:55 UTCGHSA enrichment
  17. 2026-07-03 03:24 UTCEG score recompute
  18. 2026-07-03 03:24 UTCGHSA enrichment
  19. 2026-07-02 03:09 UTCEG score recompute
  20. 2026-07-02 03:09 UTCGHSA enrichment
  21. 2026-07-01 15:07 UTCEPSS rescore
  22. 2026-07-01 02:55 UTCEG score recompute
  23. 2026-07-01 02:55 UTCGHSA enrichment
  24. 2026-06-30 23:22 UTCEPSS rescore
  25. 2026-06-30 02:40 UTCEG score recompute
Show 7 more
  1. 2026-06-30 02:40 UTCGHSA enrichment
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-29 02:25 UTCEG score recompute
  4. 2026-06-29 02:25 UTCGHSA enrichment
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 02:10 UTCEG score recompute
  7. 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 19.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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