CVE-2025-12888
Constant Time Issue with Xtensa-based ESP32 and X22519
Reported by wolfssl · Published November 21, 2025
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.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| wolfssl | Alpine | 5.9.1-r0, 5.8.4-r0 |
| wolfSSL | wolfSSL | 5.8.4 |
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| wolfSSL | wolfSSL | 0 |
| wolfSSL | wolfSSL | 0 |
Timeline
- Nov 21, 2025 CVE Published
- Nov 22, 2025 EPSS Score (30 in total, the first dated here)
- Nov 22, 2025 Coalition ESS Score (10 in total, the first dated here)
- Dec 6, 2025 CVE Updated
- Jun 2, 2026 Security Advisory
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2025-12888
vulnetix vdb fixes CVE-2025-12888Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
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