CVE-2026-55962: TLS 1.3 post-handshake authentication: server accepts Finished without client Certificate/CertificateVerify

Overview

Severity

Medium (CVSS 6.5)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-07-01

EPSS Score

0.14% (percentile: 4.0%)

Affected Products (1)

Other

• 21516-17084

Revision History

• 2026-07-01: Information published.