CVE-2026-66032

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-24. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — Patch released 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.

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.

CVSS v3
8.8
EG Score
8.8(high)
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 24, 2026

Last Modified

July 28, 2026

Advisory Details (3)

Auto-updated Jul 24, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

libssh2 Double-Free Heap Corruption via sftp_open() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/libssh2-double-free-heap-corruption-via-sftp-open
github_pr

Prevent dangling pointer by nullifying data

Fix merged in libssh2/libssh2 PR #2180 on 2026-07-02 — awaiting tagged release

https://github.com/libssh2/libssh2/pull/2180
github_commit

commit 5e4776146552 (libssh2/libssh2)

Fix landed in libssh2/libssh2 commit 5e4776146552 — awaiting tagged release

https://github.com/libssh2/libssh2/commit/5e4776146552d898b9c0e1b313cd093fa8dc92d0

Vendor Advisories for CVE-2026-66032(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
redhatlibssh2-main-1.11.1-10.2.hum12026-07-27redhat

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.

Data Freshness Timeline

(refreshed 18× in last 7d / 18× 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. 2026-07-28 01:30 UTCVendor advisory
  2. 2026-07-28 01:30 UTCGHSA enrichment
  3. 2026-07-27 22:50 UTCEG score recompute
  4. 2026-07-27 22:49 UTCGHSA enrichment
  5. 2026-07-27 14:14 UTCEPSS rescore
  6. 2026-07-27 11:39 UTCGHSA enrichment
  7. 2026-07-27 00:45 UTCEG score recompute
  8. 2026-07-27 00:45 UTCGHSA enrichment
  9. 2026-07-26 14:54 UTCEPSS rescore
  10. 2026-07-26 14:54 UTCEPSS rescore
  11. 2026-07-26 13:50 UTCEG score recompute
  12. 2026-07-26 13:50 UTCGHSA enrichment
  13. 2026-07-26 02:56 UTCEG score recompute
  14. 2026-07-26 02:56 UTCGHSA enrichment
  15. 2026-07-25 14:18 UTCEPSS rescore
  16. 2026-07-25 14:18 UTCEPSS rescore
  17. 2026-07-24 16:53 UTCEG score recompute
  18. 2026-07-24 16:52 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66032?
CVE-2026-66032 is a high vulnerability published on July 24, 2026. libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftpopen() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSHFXPOPEN with SSHFXPSTATUS…
When was CVE-2026-66032 disclosed?
CVE-2026-66032 was first published in the National Vulnerability Database on July 24, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66032 actively exploited?
CVE-2026-66032 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 79.0% of all scored CVEs.
What is the CVSS score of CVE-2026-66032?
CVE-2026-66032 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-66032?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66032, 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

Explore the affected products and dependency analysis for CVE-2026-66032

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