CyberSecBulletin
CVE-2026-21710NVD status: Analyzed

node: Allocation of Resources Without Limits or Throttling

Published Updated By the CyberSecBulletin desk

CVE-2026-21710 is a high-severity allocation of resources without limits or throttling vulnerability in node from Node.js, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4.*, 5.*, 6.* as the first without the flaw, so updating node to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 25.4% chance of exploitation within 30 days, which is in the top 2.02% of all scored CVEs.

Patch this week

EPSS places it among the vulnerabilities most likely to be exploited soon.

What to do

  1. Update node to 4.* or 5.* or 6.* or 7.*, whichever matches your release line, or a later version.
  2. Read the advisory on nodejs.org for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Node.jsnode20.20.1 and earlier; 22.22.1 and earlier; 24.14.0 and earlier; 25.8.1 and earlier; 4.0 up to, but not including, 4.*; 5.0 up to, but not including, 5.*; 6.0 up to, but not including, 6.*; 7.0 up to, but not including, 7.*; and 12 more ranges4.*, 5.*, 6.*, 7.*, 8.*, 9.*
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10.0 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.4 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified in the recordNot stated
Node.jsNode.js20.20.1 and earlier; 22.0.0 through 22.22.1; 24.0.0 through 24.14.0; 25.0.0 through 25.8.1Not stated
Red HatEnterprise Linux8.0; 9.0; 10.0Not stated
Red HatEnterprise Linux EUS9.4; 9.6; 10.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA
CVSS 3.07.5HighCNA (hackerone.com)

Official description

A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`. When this occurs, `dest["__proto__"]` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`. * This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How developers prevent this class of flaw

  • Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
  • Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other references

Other vulnerabilities in node

All node vulnerabilities

Recent Allocation of Resources Without Limits or Throttling vulnerabilities

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