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Public proof of conceptFix available

CVE-2026-21877

A public proof of concept exists; no exploitation attested.

  • Published2026-01-08
  • Fixed in1.121.3
  • WeaknessCWE-434 · CWE-94

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

n8n is an open source workflow automation platform. In versions 0.121.2 and below, an authenticated attacker may be able to execute malicious code using the n8n service. This could result in full compromise and can impact both self-hosted and n8n Cloud instances. This issue is fixed in version 1.121.3. Administrators can reduce exposure by disabling the Git node and limiting access for untrusted users, but upgrading to the latest version is recommended.

Timeline

dates in UTC
  1. 2026-01-0801:15CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-21877?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-21877?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
N8n
BranchAffectedFixed in
1.121≥ 0.123.0, < 1.121.31.121.3

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update N8n to 1.121.3

Advisories and patches

Detection

read 2026-10-23 19:25 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
2 repositories, unverifiedCVEs-Labs/CVE-2026-21877monkeontheroof/cve-2026-21877-rce
PoC-in-GitHub

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionnone2026-01-08
  • OpenCVESSVC decisionnone—
  • CNACVSS 3.19.9read 2026-10-23
  • CNAweakness (CWE)CWE-434, CWE-94read 2026-10-23
  • FIRST EPSSEPSS score5.4 %2026-10-22
  • PoC-in-GitHubproof of concept2read 2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Published
2026-01-08
Last Modified
2026-06-17
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-21877?

n8n is an open source workflow automation platform. In versions 0.121.2 and below, an authenticated attacker may be able to execute malicious code using the n8n service. This could result in full compromise and can impact both self-hosted and n8n Cloud instances. This issue is fixed in version 1.121.3. Administrators can reduce exposure by disabling the Git node and limiting access for untrusted users, but upgrading to the latest version is recommended.

Is CVE-2026-21877 actively exploited?

Active exploitation of CVE-2026-21877 has not been confirmed. Its EPSS score was 5.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-21877?

CVE-2026-21877 has a CVSS v3 base score of 9.9 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

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