CVE-2026-21717 Details
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**.
A vulnerability in the V8 JavaScript engine's string hashing process allows integer-like strings to be hashed as their numeric equivalents, creating predictable hash collisions. This flaw can be exploited by sending requests that generate multiple collisions, disrupting the Node.js process's performance. The issue commonly arises when `JSON.parse()` is used on input controlled by the attacker, as this automatically converts short strings into the vulnerable hash table. This vulnerability impacts Node.js versions 20.x, 22.x, 24.x, and 25.x.
Users can update to Node.js versions 20.20.2, 22.22.2, 24.14.1, or 25.8.2, all of which include the necessary fix.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Mar 30, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://nodejs.org/en/blog/vulnerability/march-2026-security-releases | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-328 | Use of Weak Hash | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| nodejs node.js | <= 20.20.1 >= 22.0.0, <= 22.22.1 >= 24.0.0, <= 24.14.0 >= 25.0.0, <= 25.8.1 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 19, 2026 | Initial Analysis | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 10, 2026 | CVE Modified | CISA-ADP |
| Mar 30, 2026 | New CVE Received | [email protected] |