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CVE-2026-21713

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This is a free service offered by Red Hot Cyber to the community. It allows you to view, on a single page, information about a single CVE from the National Vulnerability Database (NVD) and the National Institute of Standards and Technology (NIST) of the United States of America, the Forum of Incident Response and Security Teams (FIRST) regarding the EPSS score and percentile, data from the KEV catalog of the Cybersecurity and Infrastructure Security Agency (CISA), as well as selected resources from Red Hot Cyber and other international sources.

National Vulnerability Database Information

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**.

CVSS Base Score: 5.9 (v3.0)

The **CVSS Base Score** is a score from **0 to 10** that represents the intrinsic severity of a vulnerability. A higher score indicates greater severity.

Value
0.02.55.07.510.0
Published on: 03/30/2026 20:16:19
Last modified: 05/10/2026 14:16:47
NIST: CVE source from the National Vulnerability Database (NVD)

CVSS Metrics Details

  • Base Severity: MEDIUM
  • Vector String: 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 Impact: HIGH
  • Integrity Impact: NONE
  • Availability Impact: NONE

Common Weakness Enumeration (CWE)

Database CWE: v4.18

CWE-208: Observable Timing Discrepancy ↗

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

Fonte: MITRE CWE


FIRST Information

EPSS Score: 0.0001

The **EPSS (Exploit Prediction Scoring System)** is a score from **0 to 1** that indicates the **probability** that a vulnerability will be exploited in the real world in the next 30 days. A higher value indicates a greater likelihood of exploitation.

Value
0.00.250.50.751.0

Percentile: 0.0177

The **Percentile** indicates how much higher this vulnerability's EPSS score is compared to all other vulnerabilities in the EPSS database. For example, a percentile of 0.90 (90%) means that 90% of vulnerabilities have an EPSS score equal to or lower than the current one.

Value
0.00.250.50.751.0

*Data updated as of: 2026-06-03


CISA Information (Known Exploited Vulnerabilities)

The **CISA KEV Catalog** lists vulnerabilities that have been **actively exploited in the real world**. If a CVE is present in this catalog, it indicates that the threat is immediate and mitigation should be a top priority.

CVE **CVE-2026-21713** is not present in the CISA KEV Catalog. This indicates that it is not currently classified by CISA as an actively exploited vulnerability.


Articles published on Red Hot Cyber


NVD References

Exploit PoC from GitHub

No results found on GitHub for this CVE.