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No exploitation reported

CVE-2026-128120

SvelteKit: DoS while parsing form data from a remote functions `form`

No exploitation reported by the sources we read.

  • Published2026-11-13
  • WeaknessCWE-407

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From version 2.42.0 until 3.1.1, applications using the experimental remote functions flag and a remote form function could perform quadratic synchronous work while parsing a specially crafted request with many form entries. The parsing work could block the event loop for an extended period and deny service. This issue is fixed in 3.1.1.

Timeline

dates in UTC
  1. 2026-11-1319:34CVE publishedCNA

Versions per branch

Products declared by the CNA

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • sveltejs kit
    Affected
    • = >= 2.42.0, < 3.1.1no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-13

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-128120 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 3.17.52026-11-13
  • CNAweakness (CWE)CWE-4072026-11-13
  • NVDweakness (CWE)CWE-407read 2026-11-13

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-11-13
Last Modified
2026-11-13
NVD status
Deferred

Frequently asked questions

What is CVE-2026-128120?

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. From version 2.42.0 until 3.1.1, applications using the experimental remote functions flag and a remote form function could perform quadratic synchronous work while parsing a specially crafted request with many form entries. The parsing work could block the event loop for an extended period and deny service. This issue is fixed in 3.1.1.

Is CVE-2026-128120 actively exploited?

Active exploitation of CVE-2026-128120 has not been confirmed.

What is the CVSS score for CVE-2026-128120?

CVE-2026-128120 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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