CVE-2026-21713

| EUVD-2026-17174 MEDIUM
2026-03-30 hackerone
5.9
CVSS 3.0
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CVSS Vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Lifecycle Timeline

4
Patch Released
Mar 31, 2026 - 21:13 nvd
Patch available
Analysis Generated
Mar 30, 2026 - 19:30 vuln.today
EUVD ID Assigned
Mar 30, 2026 - 19:30 euvd
EUVD-2026-17174
CVE Published
Mar 30, 2026 - 19:07 nvd
MEDIUM 5.9

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**.

Analysis

Node.js versions 20.x, 22.x, 24.x, and 25.x use non-constant-time comparison for HMAC signature verification, allowing remote attackers to infer valid HMAC values through timing oracle attacks. The vulnerability leaks information proportional to matching bytes and requires high-resolution timing measurement capability, making exploitation feasible in controlled network conditions. …

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Priority Score

30
Low Medium High Critical
KEV: 0
EPSS: +0.0
CVSS: +30
POC: 0

Vendor Status

Ubuntu

Priority: Medium
nodejs
Release Status Version
trusty needs-triage -
xenial needs-triage -
bionic needs-triage -
focal needs-triage -
jammy needs-triage -
noble needs-triage -
questing needs-triage -
upstream released 22.22.2+dfsg+~cs22.19.15-1

Debian

nodejs
Release Status Fixed Version Urgency
bullseye vulnerable 12.22.12~dfsg-1~deb11u4 -
bullseye (security) vulnerable 12.22.12~dfsg-1~deb11u7 -
bookworm, bookworm (security) vulnerable 18.20.4+dfsg-1~deb12u1 -
trixie fixed 20.19.2+dfsg-1+deb13u2 -
trixie (security) fixed 20.19.2+dfsg-1+deb13u2 -
forky vulnerable 22.22.1+dfsg+~cs22.19.15-1 -
sid fixed 22.22.2+dfsg+~cs22.19.15-1 -
(unstable) fixed 22.22.2+dfsg+~cs22.19.15-1 -

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CVE-2026-21713 vulnerability details – vuln.today

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