Vulnerability · Published Nov 21, 2025 · Assigned by wolfSSL
CVE-2025-12888Constant Time Issue with Xtensa-based ESP32 and X22519
Low 1.0
In plain English
A low-severity security flaw in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2025-12888 |
| Alpine:v3.24 | wolfssl | 5.8.4-r0 | ALPINE-CVE-2025-12888 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2025-12888 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2025-12888 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-12888 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-12888 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2025-12888 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-12888 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2025-12888 |
Affected products (as reported)
Weakness: CWE-203 · Vector: CVSS:4.0/AV:P/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:L/SA:N