CVE-2026-27125 — Svelte SSR attribute spreading includes inherited properties from prototype chain
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 fro…
Published: 2026-02-20 · CVSS: 5.3 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7