CVE-2025-66442

State: Published
Severity: 5.1 Medium
Published: Apr 1, 2026
Updated: Apr 1, 2026
Reserved: Dec 1, 2025

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.

Scores

CVSS	Score	Vector	Source
3.1	5.1 Medium	CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N	CISA-ADP

Weaknesses

CWE-385 Covert Timing Channel

Affected Products

Product	Versions
n/an/a	n/aAffected

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/

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