CVE-2025-66442
mediumIn 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.
Vendor / product: Arm — mbed tls
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.
CVSS
5.1
5.1 (CVSS v3.1)
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Severity source: NVD CVSS v3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
Timeline (UTC)
Published: 2026-04-01 20:16
Modified: 2026-11-04 22:10
NVD status: Analyzed
Last synced 2 hours ago
Verified against the source API 2026-11-04 22:37 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
arm / mbed_tls ≤4.0.0
arm / tf-psa-crypto ≤1.0.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://mbed-tls.readthedocs.io/en/latest/security-advisories/
References
- https://github.com/Mbed-TLS/TF-PSA-Crypto/releases cve@mitre.org
- https://github.com/Mbed-TLS/mbedtls/releases cve@mitre.org
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/ cve@mitre.org
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-20... cve@mitre.org
Data sources
NVD CVE API 2.0 — fetched 2026-11-04 22:37 UTC · record ↗