CVE-2025-12888: Vulnerability in X25519 constant-time cryptographic implementations due to timing side channels introduced by compiler…
CVE-2025-12888 · Severity: high · CVSS 7.5 · Published 2025-11-21
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.
No. Junglewise Threat Intelligence has no report of CVE-2025-12888 being exploited in the wild.
How severe is CVE-2025-12888?
High severity, with a CVSS score of 7.5, published 21 November 2025.
Which products and versions are affected?
Wolfssl. The advisory does not name versions.
Is there a fix for CVE-2025-12888?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-12888?
Check whether you run Wolfssl. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.