Timing Side Channel Vulnerability in X25519 Implementations on ESP32 Chips

CVE-2025-12888

What is CVE-2025-12888?

A vulnerability exists within the X25519 constant-time cryptographic implementations, leading to potential timing side channel attacks. This issue arises from compiler optimizations and limitations inherent in the CPU architecture of Xtensa-based ESP32 chips. It is highly recommended for users targeting these chips to adopt the low memory implementations of X25519, which has been set as the default for Xtensa, to mitigate the associated risks.

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