CVE-2026-21858: n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling
Impact A vulnerability in n8n allows an attacker to access files on the underlying server through execution of certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker. This could result in exposure of sensitive information stored on the system and may enable further compromise depending on deployment configuration and workflow usage.
Patches The issue has been fixed in n8n version 1.121.0. Users should upgrade to this version or later to remediate the vulnerability.
Workarounds No official workarounds are available. As a temporary mitigation, users may restrict or disable publicly accessible webhook and form endpoints until upgrading.
Other sources
n8n is an open source workflow automation platform. Versions starting with 1.65.0 and below 1.121.0 enable an attacker to access files on the underlying server through execution of certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker, resulting in exposure of sensitive information stored on the system and may enable further compromise depending on deployment configuration and workflow usage. This issue is fixed in version 1.121.0.
— NVD
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-21858?
CVE-2026-21858 is considered a high-severity vulnerability that allows unauthenticated attackers to access sensitive files on the server.
How do I fix CVE-2026-21858?
To remediate CVE-2026-21858, upgrade n8n to version 1.121.0 or later.
What vulnerabilities are associated with CVE-2026-21858?
CVE-2026-21858 is associated with the risk of unauthorized file access and potential exposure of sensitive information.
Who is affected by CVE-2026-21858?
CVE-2026-21858 affects users of n8n versions prior to 1.121.0.
Can CVE-2026-21858 lead to data breaches?
Yes, CVE-2026-21858 can lead to data breaches by allowing unauthorized access to sensitive files.