CVE-2026-34873

An issue was discovered in Mbed TLS 3.5.0 through 4.0.0

Critical · published April 1, 2026

CVSS v3.1
9.1
EPSS
0%
Percentile
35.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00420 · 35.3th percentile
Published
2026-04-01T00:00Z
EPSS history
Timeline
  • 01 APR 00:00Z
    An issue was discovered in Mbed TLS 3.5.0 through 4.0.0
    cvelistv5