CVE-2026-66034: libssh2 Heap Out-of-Bounds Read via publickey subsystem

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploit Status

Not Exploited

Patch Tuesday

2026-Jul

Released

2026-07-26

Last Updated

2026-09-15

EPSS Score

0.40% (percentile: 34.2%)

Affected Products (2)

Other

• 21559-17084
• 21500-17084

Revision History

• 2026-07-26: Information published.
• 2026-07-27: Information published.
• 2026-08-07: Information published.
• 2026-08-25: Information published.
• 2026-09-09: Information published.
• 2026-09-12: Information published.
• 2026-09-15: Information published.