Summary
Workarounds
If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors Vary, or disable shared caching for affected App Router and RSC responses.
Impact
Applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML.
CVE-2026-44576 has a CVSS score of 5.4 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (15.5.16, 16.2.5); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
We now validate and interpret RSC request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL.
Frequently Asked Questions
- What is CVE-2026-44576? CVE-2026-44576 is a medium-severity security vulnerability in next (npm), affecting versions >= 14.2.0, < 15.5.16. It is fixed in 15.5.16, 16.2.5.
- How severe is CVE-2026-44576? CVE-2026-44576 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of next are affected by CVE-2026-44576? next (npm) versions >= 14.2.0, < 15.5.16 is affected.
- Is there a fix for CVE-2026-44576? Yes. CVE-2026-44576 is fixed in 15.5.16, 16.2.5. Upgrade to this version or later.
- Is CVE-2026-44576 exploitable, and should I be worried? Whether CVE-2026-44576 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-44576 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-44576?
- Upgrade
nextto 15.5.16 or later - Upgrade
nextto 16.2.5 or later
- Upgrade