CVE-2026-33720
mediumpriority · track · 17OT risk · elevatedEPSS 0.002 · 8 %ileDEEUUSEPSS · scored 2026-10-27
n8n is an open source workflow automation platform. Prior to version 2.8.0, when the `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK` environment variable is set to `true`, the OAuth callback handler skips ownership verification of the OAuth state parameter. This allows an attacker to trick a victim into completing an OAuth flow against a credential object the attacker controls, causing the victim's OAuth tokens to be stored in the attacker's credential. The attacker can then use those tokens to execute workflows in their name. This issue only affects instances where `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` is explicitly configured (non-default). The issue has been fixed in n8n version 2.8.0. Users should upgrade to this version or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Avoid enabling `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` unless strictly required, and/ or restrict access to the n8n instance to fully trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0877n8n: Mehrere SchwachstellenDeutsch2026-03-25csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in n8n ausnutzen, um erweiterte Privilegien, einschließlich Administratorrechte, zu erlangen, um beliebigen Code auszuführen, Daten zu manipulieren, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen oder Cross-Site- und Man-in-the-Middle-Angriffe durchzuführen.
- GHSA-vpgc-2f6g-7w7xn8n Has Authorization Bypass in OAuth Callback via N8N_SKIP_AUTH_ON_OAUTH_CALLBACK2026-03-25ghsa · osvUS
## Impact When the `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK` environment variable is set to `true`, the OAuth callback handler skips ownership verification of the OAuth state parameter. This allows an attacker to trick a victim into completing an OAuth flow against a credential object the attacker controls, causing the victim's OAuth tokens to be stored in the attacker's credential. The attacker can then use those tokens to execute workflows in their name. - This issue only affects instances where `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` is explicitly configured (non-default). ## Patches The issue has been fixed in n8n version 2.8.0. Users should upgrade to this version or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Avoid enabling `N8N_SKIP_AUTH_ON_OAUTH_CALLBACK=true` unless strictly required. - Restrict access to the n8n instance to fully trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (5)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-33720cnnvd
- https://github.com/n8n-io/n8n/releasesPatchcnnvd
- https://github.com/n8n-io/n8n/security/advisories/GHSA-vpgc-2f6g-7w7xcnnvd
- https://github.com/n8n-io/n8n/security/advisories/GHSA-vpgc-2f6g-7w7xenisa_euvd
- https://github.com/n8n-io/n8n/security/advisories/GHSA-vpgc-2f6g-7w7xMitigationVendor Advisorynvd
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