Improperly Controlled Modification of Dynamically-Determined Object Attributes Affecting svelte package, versions <5.51.5
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published20 Feb 2026
- disclosed19 Feb 2026
- creditElliott Johnson
Introduced: 19 Feb 2026
NewCVE-2026-27125 (opens in a new tab)How to fix?
Upgrade svelte to version 5.51.5 or higher.
Overview
svelte is a package for building web applications.
Affected versions of this package are vulnerable to Improperly Controlled Modification of Dynamically-Determined Object Attributes in server-side rendering when attribute spreading is performed on elements. An attacker can inject unexpected attributes or cause errors in the rendered output by polluting the Object.prototype prior to rendering.
Note:
This is only exploitable if the environment's Object.prototype has already been modified before rendering occurs.