CVE-2026-128123
SvelteKit: `@sveltejs/adapter-node` crashes when proxying certain requests via `fetch`
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From version 5.5.7 until versions 5.5.8 and 6.0.1, , @sveltejs/adapter-node can attempt to add a header to an immutable request in a context that causes the server to crash, denying service to any other requests routed to that server. This issue is fixed in 5.5.8 and 6.0.1.
| CWE | CWE-248 |
| Vendor | sveltejs |
| Product | kit |
| Published | Nov 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
sveltejs / kit
>= 3.0.0-next.0, < 3.1.1 < 2.70.4
@sveltejs / adapter-node
>= 5.5.7, < 5.5.8 >= 6.0.0-next.0, < 6.0.1
References
github.com: https://github.com/sveltejs/kit/security/advisories/GHSA-rqw3-x7hx-mm3p github.com: https://github.com/sveltejs/kit/pull/17620 github.com: https://github.com/sveltejs/kit/commit/04756a1f7a4f73e34f1934895340a46de84fc164 github.com: https://github.com/sveltejs/kit/commit/0a2e58cbccdd46cac20aa5af4e2edf17e0da11dd github.com: https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected] github.com: https://github.com/sveltejs/kit/releases/tag/@sveltejs/[email protected]