Read the docs
TI-2026-56724 Aliases CVE-2026-82259GHSA-7jhg-723h-fjhx

SvelteKit 2.49.0 before 2.53.3 Denial of Service via form

Priority MEDIUM 44CWE-502Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-502.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00533 45th percentileScored 2026-11-07
Fix Fixed kit (sveltejs): 2.53.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sveltejskit2.49.0 to before 2.53.32.53.3Patch availableCNA
  • kit Vendorsveltejs Affected 2.49.0 to before 2.53.3 Fixed in 2.53.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:svelte:sveltekit:*:*:*:*:*:node.js:*:*2.49.0 to before 2.53.3Vulnerablesveltejs
  • cpe:2.3:a:svelte:sveltekit:*:*:*:*:*:node.js:*:* Versions 2.49.0 to before 2.53.3 Vulnerable ·sveltejs

Remediation

  • Fix · CNA kit (sveltejs) Fixed in 2.53.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-82259
  2. 2026-10-03 Alias added: GHSA-7jhg-723h-fjhx

References

Advisory 1

  • TI-2023-13469 SvelteKit framework has Insufficient CSRF protection for CORS requests CVSS 3.1HIGH 8.8
  • TI-2023-13464 SvelteKit has Insufficient Cross-Site Request Forgery Protection CVSS 3.1HIGH 8.8
  • TI-2026-56726 SvelteKit before 2.52.2 CPU Exhaustion via Remote Form Deserialization CVSS 4.0HIGH 8.7
  • TI-2026-56725 SvelteKit before 2.52.2 Memory Exhaustion via Remote Form Deserialization CVSS 4.0HIGH 8.7
  • TI-2026-56721 SvelteKit before 2.69.1 Denial of Service via Remote Form CVSS 4.0MEDIUM 6.9
  • TI-2026-56723 SvelteKit 2.38.0 before 2.60.1 Cross-User Data Disclosure via query.batch CVSS 4.0MEDIUM 5.9
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences