CVE-2026-34872
Published:April 01, 2026
Updated:May 16, 2026
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).
Affected Packages
mbedtls (CONAN):
Affected version(s) >=3.5.0 <3.6.6Fix Suggestion:
Update to version 3.6.6https://github.com/Mbed-TLS/mbedtls.git (GITHUB):
Affected version(s) >=mbedtls-3.5.0 <mbedtls-3.6.6Fix Suggestion:
Update to version mbedtls-3.6.6https://github.com/Mbed-TLS/mbedtls.git (GITHUB):
Affected version(s) >=v3.5.0 <v3.6.6Fix Suggestion:
Update to version v3.6.6Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Verification of Cryptographic Signature
EPSS
Base Score:
0.02