CVE-2025-66478: act2Shell (CVE-2025-55182/CVE-2025-66478)
A vulnerability affects certain React packages<sup>1</sup> 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.
<sup>1</sup> The affected React packages are: - react-server-dom-parcel - react-server-dom-turbopack - react-server-dom-webpack
Other sources
Rejected reason: This CVE is a duplicate of CVE-2025-55182.
— NVD
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-66478?
CVE-2025-66478 is considered a significant vulnerability affecting certain versions of React packages and frameworks.
How do I fix CVE-2025-66478?
To fix CVE-2025-66478, update the 'next' package to versions 16.0.7, 15.5.7, 15.4.8, 15.3.6, 15.2.6, 15.1.9, or 15.0.5 as appropriate.
Which versions are affected by CVE-2025-66478?
CVE-2025-66478 affects React packages in versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0, as well as Next.js versions 15.x and 16.x using the App Router.
What software is impacted by CVE-2025-66478?
CVE-2025-66478 impacts certain React packages and frameworks that utilize specific versions of the 'next' package.
Is there a workaround for CVE-2025-66478?
There is no published workaround for CVE-2025-66478; updating to the patched versions is recommended.