AIKIDO-2026-933319
@sveltejs/kit is vulnerable to Prototype Pollution
43
Medium Risk
This Affects:
@sveltejs/kitTL;DR
SvelteKit remote form functions handle deletion of file input fields using an attacker-influenced path. When a file input is removed and the field path contains keys like __proto__, the deletion logic walks into and mutates the object prototype. An attacker submitting a crafted path can pollute or remove properties and methods on shared prototypes, affecting later application behavior. The fix reuses the existing safe property-access mechanism so prototype keys can no longer be traversed.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and you use remote form functions with a file input that accepts arbitrary user-controlled path names.
Background info
@sveltejs/kit is vulnerable to Prototype Pollution in versions 2.44.0 - 2.69.0.
How to fix this
Upgrade the @sveltejs/kit library to the patch version.
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SOC 2Compliant
ISO 27001Compliant