SvelteKit has deserialization expansion in unvalidated `form` remote function leading to Denial of Service (experimental only)

Some relatively small inputs can cause very large files arrays in `form` handlers. If the SvelteKit application code doesn't check `files.length` or individual files' sizes and performs expensive processing with them, it can result in Denial of Service. Only users with `experimental.remoteFunctions: true` who are using the `form` function and are processing the `files` array without validation are vulnerable.

Source published

28 Feb 2026 02:04:39 UTC

Source modified

29 Aug 2026 03:55:36 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

Publisher rating · LOW