GHSA-9QR9-H5GF-34MP

A vulnerability affects certain React packages1 for versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0 and frameworks that use the affected packages, including Next.js 15.x and 16.x using the App Router. The issue is tracked upstream as CVE-2025-55182.

Fixed in:
React: 19.0.1, 19.1.2, 19.2.1
Next.js: 15.0.5, 15.1.9, 15.2.6, 15.3.6, 15.4.8, 15.5.7, 16.0.7, 15.6.0-canary.58, 16.1.0-canary.12+

The vulnerability also affects experimental canary releases starting with 14.3.0-canary.77. Users on any of the 14.3 canary builds should either downgrade to a 14.x stable release or 14.3.0-canary.76.

All users of stable 15.x or 16.x Next.js versions should upgrade to a patched, stable version immediately.

1 The affected React packages are:

• react-server-dom-parcel
• react-server-dom-turbopack
• react-server-dom-webpack

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-9QR9-H5GF-34MP 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 (15.0.5, 15.2.6, 15.3.6, 15.4.8, 16.0.7, 15.1.9, 15.5.7); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is GHSA-9QR9-H5GF-34MP? GHSA-9QR9-H5GF-34MP is a critical-severity insecure deserialization vulnerability in next (npm), affecting versions >= 14.3.0-canary.77, < 15.0.5. It is fixed in 15.0.5, 15.2.6, 15.3.6, 15.4.8, 16.0.7, 15.1.9, 15.5.7. 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-9QR9-H5GF-34MP? GHSA-9QR9-H5GF-34MP 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 next are affected by GHSA-9QR9-H5GF-34MP? next (npm) versions >= 14.3.0-canary.77, < 15.0.5 is affected.
4. Is there a fix for GHSA-9QR9-H5GF-34MP? Yes. GHSA-9QR9-H5GF-34MP is fixed in 15.0.5, 15.2.6, 15.3.6, 15.4.8, 16.0.7, 15.1.9, 15.5.7. Upgrade to this version or later.
5. Is GHSA-9QR9-H5GF-34MP exploitable, and should I be worried? Whether GHSA-9QR9-H5GF-34MP 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-9QR9-H5GF-34MP 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-9QR9-H5GF-34MP?
   • Upgrade next to 15.0.5 or later
   • Upgrade next to 15.2.6 or later
   • Upgrade next to 15.3.6 or later
   • Upgrade next to 15.4.8 or later
   • Upgrade next to 16.0.7 or later
   • Upgrade next to 15.1.9 or later
   • Upgrade next to 15.5.7 or later