CVE-2026-56348 is an n8n flaw that lets an authenticated user get the server to send credentials to hosts outside the Allowed HTTP Request Domains list. The record scores it 9.1, while n8n rates it moderate. n8n 2.20.0 fixes it, so upgrade and review who can use shared credentials.
What's affected
The n8n advisory (GHSA-3875-8gcx-7v46) lists the npm package n8n, versions before 2.20.0, with 2.20.0 as the patched version.
The affected endpoint is POST /rest/dynamic-node-parameters/options. The advisory says any authenticated user with access to a credential could cause the server to issue HTTP requests that carry that credential, bypassing the Allowed HTTP Request Domains restriction.
The score depends on the model used. The NVD record shows CVSS 3.1 at 9.1 with a changed scope. n8n states that it uses CVSS 4.0 as its primary score and rates the issue moderate at 5.3. Read both as a sign that the flaw needs a logged in user, but that the data at risk, stored credentials, is valuable.
How to check if you're exposed
Find your n8n version. In the editor, open the help menu and choose About n8n. For an npm install, run this in the install directory.
npm ls n8n
For Docker, check the image tag. Anything below 2.20.0 is affected.
Then look at who has access. Review which users can see or use credentials that have an Allowed HTTP Request Domains list. Those are the credentials this flaw works against.
Run the free in-browser dependency scan at https://gold.safeguard.sh/scan against your manifest or lockfile. It lists vulnerable packages without installing anything.
What to do now
- Upgrade n8n to 2.20.0 or later, and redeploy any container images that pin an older tag.
- Until then, restrict n8n access to fully trusted users, as the advisory suggests.
- Limit credential sharing to people who need each credential.
- Rotate credentials that were shared widely, especially those with API access to other systems.
- Review outbound traffic logs from the n8n host for requests to hosts you do not recognize.
Why it matters
The weakness is CWE-918, server side request forgery. The server can be made to make a request for the caller, and here that request carries a credential. The Allowed HTTP Request Domains setting exists to prevent that, and this endpoint did not enforce it.
It matters because workflow tools hold the keys to many systems at once. A control that limits where a credential can be sent is only useful if every path that sends it respects the limit. The record is not in CISA's Known Exploited Vulnerabilities catalog.
Try it yourself
Click through it at your own pace, or open it full screen.
Quick check
Is this exploitable without an account?
No. The advisory says the user must be authenticated and have access to the credential. That narrows the risk to insiders and compromised accounts, which are still worth planning for.
Sources
Last reviewed: 19 October 2026.
