CVE-2025-66442

EUVD-2025-209171
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.1 MEDIUM
LOCAL
HIGH
NONE
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 19.14%
Affected Products (NVD)
VendorProductVersion
armmbed_tls
𝑥
≤ 4.0.0
armtf-psa-crypto
𝑥
≤ 1.0.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
mbedtls
bookworm
unimportant
bullseye
unimportant
bullseye (security)
unimportant
forky
unimportant
sid
unimportant
trixie
unimportant
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
mbedtls
bionic
deferred
focal
deferred
jammy
deferred
noble
deferred
questing
ignored
resolute
deferred
xenial
ignored
Common Weakness Enumeration
References
https://github.com/Mbed-TLS/TF-PSA-Crypto/releases
https://github.com/Mbed-TLS/mbedtls/releases
https://mbed-tls.readthedocs.io/en/latest/security-advisories/
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-compiler-induced-constant-time-violations/