CVE-2025-12888 Constant Time Issue with Xtensa-based ESP32 and X22519
Timing side channels in X25519 on Xtensa ESP32 allow attackers to potentially recover private keys via timing analysis.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-12888?
CVE-2025-12888 is a low-severity vulnerability in Wolfssl Wolfssl, published on 21 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-203
Which versions are affected by CVE-2025-12888?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2025-12888?
No fix has been published for CVE-2025-12888 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-12888 being exploited?
There is no known exploitation of CVE-2025-12888 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2025-12888, GHSA-xmgq-3783-qgm4, UBUNTU-CVE-2025-12888.