Home/CVE/A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash col
CVE

CVE-2026-21717

A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash col

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.

MEDIUM · CVSS 5.9 EPSS 0.00033
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0

Weakness Classification

Scoring & Timeline

5.9
MEDIUM · CVSS v3.0 · support@hackerone.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD30 Mar 2026 · 08:16 PM
CVSS VectorCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

Vendor Advisories

16
suse-csafSUSE-SU-2026:1509-1
suse-csafSUSE-SU-2026:1478-1
suse-csafSUSE-SU-2026:1363-1
suse-csafSUSE-SU-2026:1371-1
suse-csafopenSUSE-SU-2026:20519-1
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
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