Vulnerability record/PUBLISHED/Published Nov 13, 2026 19:54:05 UTC

CVE-2026-128123

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.

Base score5.9/ 10

SeverityMediumCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityMedium

Attack vectorNetworkAV

Attack complexityHighAC

Privileges requiredNonePR

User interactionNoneUI

ScopeUnchangedS

Confidentiality impactNoneC

Integrity impactNoneI

Availability impactHighA

CVSS vector stringCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering AuthorityGitHub_M

Last updatedNov 13, 2026 19:54:05 UTC

PublishedNov 13, 2026 19:54:05 UTC

ReservedNov 12, 2026 22:42:47 UTC