CVE-2026-34873

CRITICAL

Mbed TLS 3.5.0-4.0.0 - Client Impersonation

Title source: llm
STIX 2.1

Description

An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.

Scores

CVSS v3 9.1
EPSS 0.0004
EPSS Percentile 12.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-287
Status published
Products (1)
arm/mbed_tls 3.5.0 - 3.6.6
Published Apr 01, 2026
Tracked Since Apr 02, 2026