7.5

CVE-2026-40074: SvelteKit's invalidated redirect in handle hook causes Denial-of-Service

Analyzed
AliasesGHSA-3f6h-2hrp-w5wx
Published 10-04-2026Last modified 14-04-2026

Vulnerability summary

CVE-2026-40074 is a high (CVSS 7.5) vulnerability in svelte kit. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 30.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.37%
0%100%
Low · -0.24 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 10-04-2026
    PublishedVulnerability first disclosed.
  2. 14-04-2026
    Last modifiedVulnerability information updated.

Description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.57.1, redirect, when called from inside the handle server hook with a location parameter containing characters that are invalid in a HTTP header, will cause an unhandled TypeError. This could result in DoS on some platforms, especially if the location passed to redirect contains unsanitized user input. This vulnerability is fixed in 2.57.1.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.37%

Chance of exploitation in the next 30 days

Percentile

30%

Versus all other CVEs

30-day change

Decrease -0.24 pp

From 0.61% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

@sveltejs1 product
  • kit< 2.57.1
Svelte1 product
Sveltejs1 product

3 vendors · 3 products

References

6 links