Medium severity · published Mar 30, 2026
CVE-2026-21717
A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable
5.9
CVSS
0.3%
EPSS
No
On KEV
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**.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
node · nodejs
20.20.1 through 20.20.1; 22.22.1 through 22.22.1; 24.14.0 through 24.14.0; 25.8.1 through 25.8.1; 4.0 before 4.*; 5.0 before 5.*; +14 more · source: vendor
NO
Node.js · Nodejs
through 20.20.1; 22.0.0 through 22.22.1; 24.0.0 through 24.14.0; 25.0.0 through 25.8.1 · source: NVD
Affected product
NO
node
nodejs
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