CVE-2025-12888

High · 7.5

CVSS

7.5

EPSS

0.3%

Published

Nov 21, 2025

CISA due date

—

The record

Vulnerability in X25519 constant-time cryptographic implementations due to timing side channels introduced by compiler optimizations and CPU architecture limitations, specifically with the Xtensa-based ESP32 chips. If targeting Xtensa it is recommended to use the low memory implementations of X25519, which is now turned on as the default for Xtensa.

Affected packages

Ecosystem	Package	Introduced	Fixed