CVE-2026-21717 - Vulnerability Details - OpenCVE

A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process.

The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table.

This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.

No CVSS v4.0

No CVSS v3.1

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

No data.

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Advisories

Source	ID	Title
Debian DSA	DSA-6183-1	nodejs security update

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://nodejs.org/en/blog/vulnerability/march-2026-security-releases

History

Mon, 30 Mar 2026 19:30:00 +0000

Type	Values Removed	Values Added
Description		A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process. The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table. This vulnerability affects 20.x, 22.x, 24.x, and 25.x.
References		https://nodejs.org/en/blog/vulnerability/march-2026-security-releases
Metrics		cvssV3_0 `{'score': 5.9, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}`

Projects

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MITRE

Status: PUBLISHED

Assigner: hackerone

Published: 2026-03-30T19:07:28.415Z

Updated: 2026-03-30T19:46:10.357Z

Reserved: 2026-01-04T15:00:06.575Z

Link: CVE-2026-21717

Vulnrichment

No data.

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

No weakness.

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