# CVE-2025-67647: @sveltejs/kit XSS — Fixed in 2.49.5

📦 npm

Not in CISA KEV

# CVE-2025-67647 — @sveltejs/kit

[Fix: sveltejs/kit@d9ae9b0](https://github.com/sveltejs/kit/commit/d9ae9b00b14f5574d109f3fd548f960594346226)

CVE-2025-67647 is a CWE-248 vulnerability in @sveltejs/kit. A fix is available for @sveltejs/kit — see the affected versions and patch details below.

SvelteKit Denial of service and possible SSRF when using prerendering

Also known as[GHSA-j62c-4x62-9r35](/vulnerability/GHSA-j62c-4x62-9r35)

Published

Jan 15, 2026

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

## Exploitation Status

### No confirmed exploitation observed yet

-   CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
-   CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-67647.

## EPSS Exploitation Probability

[via FIRST.org ↗](https://www.first.org/epss/)

0.6%probability of exploitation in next 30 days

Lower Risk+0.09%

Lower risk than most CVEs49th percentile — riskier than 49% of all scored CVEsHighest risk

0.00%0.37%0.74%1.11%0.0%0.6%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/).

## Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

216other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

`@sveltejs/kit`npm

5.1Mdownloads / week

`@sveltejs/adapter-node`npm

1.6Mdownloads / week

## Description

#### Summary

Versions of SvelteKit are vulnerable to a server side request forgery (SSRF) and denial of service (DoS) under certain conditions.

#### Details

Affected versions from 2.44.0 onwards are vulnerable to DoS if:

-   your app has at least one prerendered route (`export const prerender = true`)

Affected versions from 2.19.0 onwards are vulnerable to DoS and SSRF if:

-   your app has at least one prerendered route (`export const prerender = true`)
-   AND you are using `adapter-node` without a configured `ORIGIN` environment variable, and you are not using a reverse proxy that implements Host header validation

#### Impact

The DoS causes the running server process to end.

The SSRF allows access to internal services that can be reached without authentication when fetched from SvelteKit's server runtime.

It is also possible to obtain an SXSS via cache poisoning, by forcing a potential CDN to cache an XSS returned by the attacker's server (the latter being able to specify the cache-control of their choice).

#### Credits

-   Allam Rachid ([zhero;](https://zhero-web-sec.github.io/research-and-things/))
-   Allam Yasser (inzo)
-   d-xuan ([wednesday](https://d-xuan.github.io/wednesday/))

## Affected Packages

2 total 2 fixed

Ecosystem

Package

Vulnerable range

Fix

📦npm

`@sveltejs/kit` 

≥ 2.19.0&&< 2.49.5

2.49.5`npm install @sveltejs/kit@2.49.5`

📦npm

`@sveltejs/adapter-node` 

≥ 5.4.1&&< 5.5.1

5.5.1`npm install @sveltejs/adapter-node@5.5.1`

## Affected Products

2 products · 2 configurations

Application

`adapter-node`svelte

≥ 5.4.1 && < 5.5.1

range

Application

`kit`svelte

≥ 2.19.0 && < 2.49.5

range

## Detection & mitigation playbook

Open-source dependency

1.  ### Detect
    
    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/kit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
    
2.  ### Fix
    
    Update @sveltejs/kit to 2.49.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-67647 is resolved across your whole dependency graph.
    
3.  ### Workarounds
    
    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
    

## Frequently Asked Questions

\### Summary Versions of SvelteKit are vulnerable to a server side request forgery (SSRF) and denial of service (DoS) under certain conditions. ### Details Affected versions from 2.44.0 onwards are vulnerable to DoS if: - your app has at least one prerendered route (\`export const prerender = true\`) Affected versions from 2.19.0 onwards are vulnerable to DoS and SSRF if: - your app has at least one prerendered route (\`export const prerender = true\`) - AND you are using \`adapter-node\` without a configured \`ORIGIN\` environment variable, and you are not using a reverse proxy that implements H

O3 Security · Impact-Aware SCA

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