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PatchSiren cyber security CVE debrief

CVE-2026-56359 n8n CVE debrief

CVE-2026-56359 is a cross-site scripting vulnerability in n8n before 2.8.0. Authenticated users can inject malicious JavaScript URLs into OAuth2 credential Authorization URL fields. Attackers can craft malicious credentials and trick victims into clicking the OAuth authorization button, executing arbitrary scripts in their browser session with the victim's privileges. This vulnerability can have a significant impact on the security of n8n instances, and users should take steps to mitigate it.

Vendor
n8n
Product
Unknown
CVSS
MEDIUM 4.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-08
Original CVE updated
2026-07-09
Advisory published
2026-07-08
Advisory updated
2026-07-09

Who should care

Users of n8n versions before 2.8.0 should be aware of this vulnerability and take steps to mitigate it. This includes upgrading to version 2.8.0 or later and being cautious when clicking on OAuth authorization buttons. Additionally, security teams and vulnerability management teams should review the affected scope and severity of this vulnerability and plan accordingly.

Technical summary

The vulnerability exists in the credential management flow of n8n, specifically in the OAuth2 credential Authorization URL fields. Authenticated users can inject malicious JavaScript URLs, which can be used by attackers to execute arbitrary scripts in the victim's browser session. This vulnerability can be mitigated by upgrading to n8n version 2.8.0 or later and being cautious when clicking on OAuth authorization buttons.

Defensive priority

Medium

Recommended defensive actions

  • Upgrade to n8n version 2.8.0 or later
  • Be cautious when clicking on OAuth authorization buttons
  • Monitor for suspicious activity in n8n instances
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-08T14:17:16.620Z and was last modified on 2026-07-09T15:16:38.060Z. The NVD entry is currently Analyzed. This information is based on the provided source corpus and may not reflect the full scope of the vulnerability. Defenders should verify the affected scope and severity with the official CVE record and NVD entry. The vulnerability exists in n8n before 2.8.0, and users should exercise caution when using OAuth2 credential Authorization URL fields.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-08T14:17:16.620Z and has not been modified since then. The NVD entry is currently Analyzed.