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VulnerabilityCVE-2026-21877Published 2026-01-08

CVE-2026-21877 — N8n

critical

As of 2026-01-20, CVE-2026-21877 is a CRITICAL-severity vulnerability in N8n, CVSS v3.1 9.9, EPSS 14.1% (94.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-21877, most recently “n8n Multi-CVE Vulnerability Cascade — Expression Sandbox Escape, Pyodide RCE, Arbitrary File Write, Command Injection (9 CVEs, 2× CVSS 10.0)”.

CVSS v3.1
9.9/10Critical
EPSS
14.1%Higher than 94.3% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
1Campaigns referencing it
Priority
8.7/10Threadlinqs triage score
Published
Updated 2026-01-20
CVSS v3.1 9.9 (CRITICAL) · EPSS 14.1% (higher than 94.3% of all scored CVEs) · Priority 8.7/10 · Published 2026-01-08

Last updated:

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.

The record classifies CVE-2026-21877 under weakness classes CWE-94, CWE-434. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 270 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.9 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (FIRST)
14.1% probability of exploitation in the next 30 days, higher than 94.3% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
8.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-01-08, last modified 2026-01-20

Is CVE-2026-21877 being exploited?

It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-21877

The record marks a vendor fix as available for CVE-2026-21877. Patch reference: https://github.com/n8n-io/n8n/commit/f4b009d00d1f4ba9359b8e8f1c071e3d910a55f6. Vendor advisory: https://github.com/n8n-io/n8n/commit/f4b009d00d1f4ba9359b8e8f1c071e3d910a55f6. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-21877

1 tracked threat in the Threadlinqs corpus references CVE-2026-21877, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from nvd and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.