Information Exposure Through Timing Discrepancy in mbed TLS and TF-PSA-Crypto - CVE-2026-54435
Published: July 13, 2026
Vulnerability identifier: #VU137395
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-54435
CWE-ID: CWE-208
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: ARM
Affected software:
mbed TLS
TF-PSA-Crypto
mbed TLS
TF-PSA-Crypto
Detailed vulnerability description
The vulnerability allows a local privileged user to recover long-term ECC keys.
The vulnerability exists due to observable timing side-channel behavior in optimized modular reduction routines for elliptic curve operations when performing repeated scalar multiplication with the same secret scalar. A local privileged user can obtain precise execution traces to recover long-term ECC keys.
Affected operations include deterministic ECDSA signature generation, derivation of the public key when loading a private key, and deterministic key generation.
How to mitigate CVE-2026-54435
Install security update from vendor's website.