CVEvulnerability

CVE-2026-21713

5.9 MEDIUM Published 2026-03-30 Modified 2026-08-19 Official page ↗
Status
Analyzed
Published
2026-03-30
Last modified
2026-08-19
Assigner
[email protected]
CVSS 3.0 ([email protected])
5.9 MEDIUM — CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
CWE-208

Description

A flaw in Node.js HMAC verification uses a non-constant-time comparison when validating user-provided signatures, potentially leaking timing information proportional to the number of matching bytes. Under certain threat models where high-resolution timing measurements are possible, this behavior could be exploited as a timing oracle to infer HMAC values. Node.js already provides timing-safe comparison primitives used elsewhere in the codebase, indicating this is an oversight rather than an intentional design decision. This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.

Affected configurations

• nodejs node.js (<= 20.20.1) • nodejs node.js (>= 22.0.0 <= 22.22.1) • nodejs node.js (>= 24.0.0 <= 24.14.0) • nodejs node.js (>= 25.0.0 <= 25.8.1)

Related

Weakness · CWE (1)

  • CWE-208 Observable Timing Discrepancy weakness

References