CVE-2025-12888

Constant Time Issue with Xtensa-based ESP32 and X22519

Published Nov 21, 2025 CVSS 4.0 · 1 Low EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:wolfssl:wolfssl:5.8.2:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Wolfssl
Wolfssl wolfssl
Vendors & Products Wolfssl
Wolfssl wolfssl
Type Values Removed Values Added
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.
Title Constant Time Issue with Xtensa-based ESP32 and X22519
Weaknesses CWE-203
References
Metrics cvssV4_0

{'score': 1, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
wolfSSL
Published
Updated
Dec 8, 2025, 3:51 PM
Reserved
Nov 7, 2025, 5:36 PM
Status
Analyzed
Published
Nov 21, 2025, 11:15 PM
Modified
Oct 19, 2026, 1:10 PM