Information Exposure Through Timing Discrepancy in TF-PSA-Crypto and mbed TLS - CVE-2026-54435

 

Information Exposure Through Timing Discrepancy in TF-PSA-Crypto and mbed TLS - CVE-2026-54435

Published: July 13, 2026


Vulnerability identifier: #VU137395
CSH Severity: Low
CVSS v4: 5.6 [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]
CVE-ID: CVE-2026-54435
CWE-ID: CWE-208
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

TF-PSA-Crypto
mbed TLS

How to mitigate CVE-2026-54435

Install security update from vendor's website.

TF-PSA-Crypto - addressed in versions 1.1.1, 1.2.0
mbed TLS - addressed in versions 3.6.7, 4.1.1, 4.2.0

External References

Related Security Bulletins