vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2025-12888

Constant Time Issue with Xtensa-based ESP32 and X22519

HIGH
7.5
CVSS Score
Published: November 21, 2025 at 10:50 PM UTC
Updated: October 19, 2026 at 01:10 PM UTC
1 product affected across 1 vendorwolfSSL

Using wolfSSL by wolfSSL?

Get instant alerts when new vulnerabilities affect wolfSSL - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

wolfSSL· Wolfssl
95%
5.8.2
Affected range stops below 5.8.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

Broken Link
Source: cverecord
https://https://github.com/wolfSSL/wolfssl/pull/9275

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-203

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card