CVE search · CVE-2026-21713
CVE-2026-21713
medium 5.9
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**.
Details
- Status
- Analyzed
- Published
- Last changed
- Source
- support@hackerone.com
- Weakness
- CWE-208
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 3.0 | medium 5.9 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
support@hackerone.comSecondary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
- nodejs · node.js