Vulnerability Description
SvelteKit versions from 2.49.0 through 2.53.2 (fixed in 2.53.3) contain a deserialization expansion issue in the experimental form remote function. When an application enables experimental.remoteFunctions and uses the form function to process the files array without validating files.length or individual file sizes, an attacker can submit relatively small inputs that expand into very large file arrays, leading to expensive processing and denial of service.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Svelte | Sveltekit | >= 2.49.0, < 2.53.3 |
Related Weaknesses (CWE)
References
- https://github.com/sveltejs/kit/security/advisories/GHSA-fpg4-jhqr-589cVendor Advisory
- https://www.vulncheck.com/advisories/sveltekit-2.49.0-before-2.53.3-denial-of-seThird Party Advisory
FAQ
What is CVE-2026-82259?
CVE-2026-82259 is a vulnerability with a CVSS score of 7.5 (HIGH). SvelteKit versions from 2.49.0 through 2.53.2 (fixed in 2.53.3) contain a deserialization expansion issue in the experimental form remote function. When an application enables experimental.remoteFunct...
How severe is CVE-2026-82259?
CVE-2026-82259 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-82259?
Check the references section above for vendor advisories and patch information. Affected products include: Svelte Sveltekit.