Security Update: Multiple vulnerabilities in SvelteKit

Netlify · Jan 15, 2026

The Svelte team has disclosed five CVEs affecting the Svelte and SvelteKit ecosystem. Here's what Netlify customers need to know. Vulnerabilities

CVE-2026-22775 : Memory/CPU exhaustion in devalue (5.1.0–5.6.1)
CVE-2026-22774 : Memory exhaustion in devalue (5.3.0–5.6.1)
CVE-2026-22803 : Server crash in @sveltejs/kit (2.49.0–2.49.4)
CVE-2025-67647 : Server crash and SSRF in @sveltejs/kit (2.44.0–2.49.4) and @sveltejs/adapter-node (2.19.0–2.49.4)
CVE-2025-15265 : XSS in svelte (5.46.0–5.46.3)

Impact on Netlify CVE-2026-22775, CVE-2026-22774, and CVE-2026-22803 These are server-side denial-of-service (DoS) vulnerabilities. On Netlify, these have minimal impact: our autoscaling serverless architecture means that a malicious request resulting in a crashed or hung function does not affect other requests. However, active exploitation could increase your function costs. In addition, note that only sites using the experimental Remote Functions feature are affected. CVE-2025-67647 As above, this DoS vulnerability involves intentionally "crashing" a server. On Netlify, this has minimal impact. The SSRF vulnerability affects a @sveltejs/adapter-node, which is not used by apps deployed to Netlify. CVE-2025-15265 This is a client-side cross-site scripting (XSS) vulnerability. Regardless of hosting provider, all apps using the experimental hydratable with unsanitized user-controlled keys are vulnerable. What should I do? Although the impact to Netlify sites is limited in this case, we always strongly recommend upgrading as soon as possible to patched releases:

devalue 5.6.2 or later
@sveltejs/kit 2.49.5 or later
@sveltejs/adapter-node 5.5.1 or later
svelte 5.46.4 or later

Resources

Svelte team disclosure