CVE-2026-27125

CVE-2026-27125 · Svelte SSR attribute spreading includes inherited properties from prototype chain

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svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted — a precondition outside of Svelte's control — this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.

CVSS 5.3 · Medium · EPSS 0.4% · Fix available

Published

2026-02-20T22:29:45.364Z

Updated

2026-02-25T21:33:14.822Z

Stack: node

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