Answer in brief
CVE-2026-27125 records a Medium severity vulnerability in Svelte SSR attribute spreading includes inherited properties from prototype chain. The current sources do not mark it as known exploited. The current feed maps svelte (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps svelte (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| sveltenpm | <=5.51.4 | Not reported |
Published upstream
Feb 18, 2026
Evidence: source:ghsa:source_dates:source-dates:recordSource modified
Feb 18, 2026
Evidence: source:ghsa:source_dates:source-dates:recordFirst seen by HOL
Aug 25, 2026
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.
Quoted source text, attributed separately from HOL analysis.