Skip to content
Fencer Intel
medium 5.4

CVE-2026-126389 json

n8n before 1.123.89 Authentication Bypass via Chat Trigger Embedded Chat

published 18d ago modified 2d ago also EUVD-2026-125176 , GHSA-pwj5-wwm6-g83j

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository n8n-io/n8n. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

n8n before 1.123.89 contains an authentication bypass vulnerability in the Chat Trigger that allows unauthenticated attackers to skip n8n User Auth through the setup GET webhook route in embedded chat mode. Attackers can send unauthenticated GET requests to the chat webhook URL to read named session conversation history or trigger workflows with attacker-supplied input.

Patch / fix

  • npm n8n >= 1.123.89, >= 2.45.5, >= 2.46.1, >= 3.0.1
  • n8n-io n8n 1.123.89, 2.45.5, 2.46.1, 3.0.1

Is CVE-2026-126389 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm n8n
<1.123.89
<2.46.1
<2.45.5
<3.0.1
>= 1.123.89
>= 2.46.1
>= 2.45.5
>= 3.0.1

Affected products

  • n8n-io n8n

Classification

Weakness
  • CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of n8n-io/n8n published their own advisory on GitHub. Reviewed sources take precedence over it.