CVE-2025-66442

MEDIUM

Mbed TLS <4.0.0 - Timing Side Channel

Title source: llm

Description

In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected.

References (4)

Core 4

Core References

https://github.com/Mbed-TLS/mbedtls/releases

https://mbed-tls.readthedocs.io/en/latest/security-advisories/

https://github.com/Mbed-TLS/TF-PSA-Crypto/releases

https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-compiler-induced-constant-time-violations/

Scores

CVSS v3 5.1

EPSS 0.0002

EPSS Percentile 6.9%

Attack Vector LOCAL

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-385

Status published

Products (2)

arm/mbed_tls < 4.0.0

arm/tf-psa-crypto < 1.0.0

Published Apr 01, 2026

Tracked Since Apr 02, 2026