CVE-2026-21717

MEDIUM
5.9
CVSS Score
Published: March 30, 2026 at 07:07 PM UTC
Updated: August 19, 2026 at 02:45 PM UTC
1 product affected across 1 vendorNode.js

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 20.20.110.0 ≤ v < 10.*11.0 ≤ v < 11.*12.0 ≤ v < 12.*13.0 ≤ v < 13.*14.0 ≤ v < 14.*15.0 ≤ v < 15.*16.0 ≤ v < 16.*17.0 ≤ v < 17.*18.0 ≤ v < 18.*19.0 ≤ v < 19.*22.0.0 ≤ v ≤ 22.22.124.0.0 ≤ v ≤ 24.14.025.0.0 ≤ v ≤ 25.8.14.0 ≤ v < 4.*5.0 ≤ v < 5.*6.0 ≤ v < 6.*7.0 ≤ v < 7.*8.0 ≤ v < 8.*9.0 ≤ v < 9.*10.011.012.013.014.015.016.017.018.019.020.20.122.22.124.14.025.8.14.05.06.07.08.09.0
Affected range stops below 10.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 11.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 12.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 13.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 14.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 17.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 18.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 19.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.*, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-328

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