CVE-2026-66035: libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

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

2026-08-07

EPSS Score

0.47% (percentile: 39.3%)

Affected Products (1)

Other

• 21559-17084

Revision History

• 2026-07-26: Information published.
• 2026-07-27: Information published.
• 2026-08-07: Information published.