n8n Has Authorization Bypass in OAuth Callback via N8N_SKIP_AUTH_ON_OAUTH_CALLBACK

CVE-2026-33720 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

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.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-25 21:57:55 UTC
Updated
2026-03-25 21:57:55 UTC
GitHub reviewed
2026-03-25 21:57:55 UTC
NVD published
2026-03-25

EPSS Score

Score Percentile
0.01% 1.46%

CVSS Scores

Base score Version Severity Vector
4.7 3.1 —
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
6.3 4.0 —
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:L)
Limited confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:L)
Limited confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:L)
Limited integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-vpgc-2f6g-7w7x ↗
CVE CVE-2026-33720 ↗

CWEs

CWE id Name
CWE-863 Incorrect Authorization

Credits

  • subhanUmer (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm n8n < 2.8.0 2.8.0 —

References

cvelogic Threat Intelligence