CVE-2026-55199: libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler

Overview

Severity
Medium (CVSS 5.9)
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Status
Not Exploited
Patch Tuesday
2026-Jun
Released
2026-06-27
Last Updated
2026-06-28
EPSS Score
0.41% (percentile: 32.6%)

Affected Products (4)

Other

  • 21431-17084
  • 21485-17084
  • 21318-17084
  • 20881-17084

Revision History

  • 2026-06-27: Information published.
  • 2026-06-28: Information published.