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Next has a Denial of Service with Server Components - Incomplete Fix Follow-Up

High severity GitHub Reviewed Published Dec 11, 2025 in vercel/next.js • Updated Jan 15, 2026

Package

npm next (npm)

Affected versions

>= 13.3.1-canary.0, < 14.2.35
>= 15.0.6, < 15.0.7
>= 15.1.10, < 15.1.11
>= 15.2.7, < 15.2.8
>= 15.3.7, < 15.3.8
>= 15.4.9, < 15.4.10
>= 15.5.8, < 15.5.9
>= 15.6.0-canary.59, < 15.6.0-canary.60
>= 16.0.9, < 16.0.10
>= 16.1.0-canary.17, < 16.1.0-canary.19

Patched versions

14.2.35
15.0.7
15.1.11
15.2.8
15.3.8
15.4.10
15.5.9
15.6.0-canary.60
16.0.10
16.1.0-canary.19

Description

It was discovered that the fix for CVE-2025-55184 in React Server Components was incomplete and did not fully mitigate denial-of-service conditions across all payload types. As a result, certain crafted inputs could still trigger excessive resource consumption.

This vulnerability affects React versions 19.0.2, 19.1.3, and 19.2.2, as well as frameworks that bundle or depend on these versions, including Next.js 13.x, 14.x, 15.x, and 16.x when using the App Router. The issue is tracked upstream as CVE-2025-67779.

A malicious actor can send a specially crafted HTTP request to a Server Function endpoint that, when deserialized, causes the React Server Components runtime to enter an infinite loop. This can lead to sustained CPU consumption and cause the affected server process to become unresponsive, resulting in a denial-of-service condition in unpatched environments.

References

@feedthejim feedthejim published to vercel/next.js Dec 11, 2025
Published by the National Vulnerability Database Dec 12, 2025
Published to the GitHub Advisory Database Dec 12, 2025
Reviewed Dec 12, 2025
Last updated Jan 15, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

Weaknesses

Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource. Learn more on MITRE.

Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. Learn more on MITRE.

Dependency on Vulnerable Third-Party Component

The product has a dependency on a third-party component that contains one or more known vulnerabilities. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-5j59-xgg2-r9c4

Source code

Credits

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