CVE-2026-40073: SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte

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HIGH 7.5REMOTEUPGRADE

CVE-2026-40073 is a high-severity flaw (CVSS 7.5) affecting kit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.57.1, under certain circumstances, requests could bypass the BODY_SIZE_LIMIT on SvelteKit applications running with adapter-node. This bypass does not affect body size limits at other layers of the application stack, so limits enforced in the WAF, gateway, or at the platform level are unaffected. This vulnerability is fixed in 2.57.1.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-770
Published	2026-04-10
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: svelte

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-10 17:17 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

svelte kit UPGRADE

Affected: < 2.57.1

Fixed in: 2.57.1

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls kit

2. UPGRADE to 2.57.1

npm install kit@">=2.57.1"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40073?

kit: upgrade to 2.57.1. Exact commands for each OS are on this page.

Is CVE-2026-40073 being exploited?

CVE-2026-40073 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40073 affect?

CVE-2026-40073 affects kit. Severity is high (CVSS 7.5). SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.57.1, under certain circumstances, requests could bypass the BODY_SIZE_LIMIT on SvelteKit applications running with adapter-node. T

How urgent is CVE-2026-40073?

Priority 42/100. High severity; Remotely exploitable, no login, no user action

References

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