Denial of Service Vulnerability in SvelteKit by SvelteJS
CVE-2026-82259

8.7HIGH

Key Information:

Vendor

Sveltejs

Status
Kit
Vendor
CVE Published:
28 August 2026

What is CVE-2026-82259?

SvelteKit versions 2.49.0 through 2.53.2 contain a deserialization expansion vulnerability within the experimental form remote function. This issue arises when applications using experimental.remoteFunctions do not validate the 'files' array's length or individual file sizes. Consequently, an attacker may exploit this oversight by submitting small inputs that expand into massive file arrays, potentially leading to resource exhaustion and a denial of service in the application.

Affected Version(s)

kit 2.49.0 < 2.53.3

kit 2.53.3

References

https://github.com/sveltejs/kit/security/advisories/GHSA-...
vendor-advisory
https://www.vulncheck.com/advisories/sveltekit-2.49.0-bef...
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

elliott-with-the-longest-name-on-github
jviide
.