What’s Vulnerable › Vulnerabilities
CVE-2026-21717
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-30 · updated 2026-08-19
- Weakness: CWE-328
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**.
Affected products
- Node.js: through 20.20.1; from 22.0.0 through 22.22.1; from 24.0.0 through 24.14.0; from 25.0.0 through 25.8.1
References
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