CVE-2026-44576
Description
A flaw was found in Next.js, a React framework for building web applications. This vulnerability, related to cache poisoning, affects applications utilizing React Server Components (RSC) when shared caches fail to properly partition response variants. A remote attacker can exploit this by causing an RSC response to be served from its original URL, thereby poisoning shared cache entries. As a result, subsequent visitors may receive unexpected component payloads instead of the intended HTML content.
Mitigation
To address this cache poisoning vulnerability in Next.js applications utilizing React Server Components, ensure that any shared caching mechanisms are configured to correctly partition responses. This involves defining cache keys that incorporate all relevant request parameters and headers to prevent serving incorrect content from the cache. Review the documentation for your specific caching solution (e.g., CDN, reverse proxy, or application-level cache) to implement robust cache key strategies and variant handling. Improper cache configuration can lead to an attacker poisoning cache entries, affecting subsequent users.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | N/A | 5.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Changed |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L
Understanding the Weakness (CWE)
Integrity,Non-Repudiation,Access Control
Technical Impact: Unexpected State; Hide Activities; Bypass Protection Mechanism
An attacker could create HTTP messages to exploit a number of weaknesses including 1) the message can trick the web server to associate a URL with another URL's webpage and caching the contents of the webpage (web cache poisoning attack), 2) the message can be structured to bypass the firewall protection mechanisms and gain unauthorized access to a web application, and 3) the message can invoke a script or a page that returns client credentials (similar to a Cross Site Scripting attack).
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
