GHSA-FMH4-WR37-44FP

@vitejs/plugin-rsc vendors react-server-dom-webpack, which contained an unauthenticated remote code execution vulnerability in versions prior to 19.0.1, 19.1.2, and 19.2.1. See details in React repository's advisory https://github.com/facebook/react/security/advisories/GHSA-fv66-9v8q-g76r

Recommendations

Upgrade immediately to @vitejs/[email protected] or later.

Workarounds

Applications not using server-side React or React Server Components are unaffected.

Applications using affected versions of @vitejs/plugin-rsc are vulnerable to unauthenticated remote code execution through deserialization of untrusted data. An attacker can execute arbitrary code remotely without authentication, affecting confidentiality, integrity, and availability.

Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.

GHSA-FMH4-WR37-44FP has a CVSS score of 10.0 (Critical). 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 (0.5.3); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is GHSA-FMH4-WR37-44FP? GHSA-FMH4-WR37-44FP is a critical-severity insecure deserialization vulnerability in @vitejs/plugin-rsc (npm), affecting versions <= 0.5.2. It is fixed in 0.5.3. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
2. How severe is GHSA-FMH4-WR37-44FP? GHSA-FMH4-WR37-44FP has a CVSS score of 10.0 (Critical). 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.
3. Which versions of @vitejs/plugin-rsc are affected by GHSA-FMH4-WR37-44FP? @vitejs/plugin-rsc (npm) versions <= 0.5.2 is affected.
4. Is there a fix for GHSA-FMH4-WR37-44FP? Yes. GHSA-FMH4-WR37-44FP is fixed in 0.5.3. Upgrade to this version or later.
5. Is GHSA-FMH4-WR37-44FP exploitable, and should I be worried? Whether GHSA-FMH4-WR37-44FP 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
6. What actually determines whether GHSA-FMH4-WR37-44FP 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.
7. How do I fix GHSA-FMH4-WR37-44FP? Upgrade @vitejs/plugin-rsc to 0.5.3 or later.

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