CVE-2026-34872

Published Apr 1, 2026

Last updated 12 days ago

Overview

Description
An issue was discovered in Mbed TLS 3.5.x and 3.6.x through 3.6.5 and TF-PSA-Crypto 1.0. There is a lack of contributory behavior in FFDH due to improper input validation. Using finite-field Diffie-Hellman, the other party can force the shared secret into a small set of values (lack of contributory behavior). This is a problem for protocols that depend on contributory behavior (which is not the case for TLS). The attack can be carried by the peer, or depending on the protocol by an active network attacker (person in the middle).
Source
cve@mitre.org
NVD status
Analyzed
Products
mbed_tls, tf-psa-crypto

Risk scores

CVSS 3.1

Type
Secondary
Base score
9.1
Impact score
5.2
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity
CRITICAL

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-347

Social media

Hype score
Not currently trending

Configurations