Svelte SSR attribute spreading includes inherited properties from prototype chain
cve-program · CVE-2026-27125
Publishedsvelte 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.
Read the publisher's advisoryeuvd · EUVD-2026-7765
Publishedsvelte 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.
Read the publisher's advisorynvd · CVE-2026-27125
Publishedsvelte 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.
Read the publisher's advisoryosv · GHSA-crpf-4hrx-3jrp
PublishedIn 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.
Read the publisher's advisoryAffected versions, risk and source history
Related advisories and sources
Publishers link these advisories through the identifiers shown below. A shared identifier or date alone does not tell you whether your software is affected or whether the advisories describe the same cause.
CVE-2026-27125 · CVE overview and exploitation status
cve-program · CVE-2026-27125
- https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp
- https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f
- https://github.com/sveltejs/svelte/releases/tag/[email protected]
euvd · EUVD-2026-7765
- https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp
- https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f
- https://github.com/sveltejs/svelte/releases/tag/[email protected]
nvd · CVE-2026-27125
- https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f
- https://github.com/sveltejs/svelte/releases/tag/[email protected]
- https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp
osv · GHSA-crpf-4hrx-3jrp
- https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp
- https://nvd.nist.gov/vuln/detail/CVE-2026-27125
- https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f
- https://github.com/sveltejs/svelte
- https://github.com/sveltejs/svelte/releases/tag/[email protected]
Related changes
Linked by CVE identifierNo related changes are available here.