CVE-2026-27495: n8n has a Sandbox Escape in its JavaScript Task Runner

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.8%, percentile 57: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 57% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes n8n (npm) < 1.123.22, fixed in 1.123.22; n8n (npm) >= 2.0.0, < 2.9.3, fixed in 2.9.3; n8n (npm) >= 2.10.0, < 2.10.1, fixed in 2.10.1. Check your lockfile, including transitive dependencies.

What it is

n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, an authenticated user with permission to create or modify workflows could exploit a vulnerability in the JavaScript Task Runner sandbox to execute arbitrary code outside the sandbox boundary. On instances using internal Task Runners (default runner mode), this could result in full compromise of the n8n host. On instances using external Task Runners, the attacker might gain access to or impact other task executed on the Task Runner. Task Runners must be enabled using N8NRUNNERSENABLED=true. The issue has been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations. Limit workflow creation and editing permissions to fully trusted users only, and/or use external runner mode (N8NRUNNERSMODE=external) to limit the blast radius. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

From the GitHub advisory

Impact An authenticated user with permission to create or modify workflows could exploit a vulnerability in the JavaScript Task Runner sandbox to execute arbitrary code outside the sandbox boundary.

On instances using internal Task Runners (default runner mode), this could result in full compromise of the n8n host. On instances using external Task Runners, the attacker might gain access to or impact other task executed on the Task Runner. - Task Runners must be enabled using N8NRUNNERSENABLED=true.

Patches The issue has been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Limit workflow creation and editing permissions to fully trusted users only. - Use external runner mode (N8NRUNNERSMODE=external) to limit the blast radius.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Weakness type: CWE-94.

Product: n8n (npm) · Assigned by: GitHub_M · Published: 2026-02-25

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: low (any account)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.84% probability of exploitation activity in the next 30 days; percentile 57.

Timeline

• 2026-02-25 — CVE record published by GitHub_M
• 2026-02-25 — GitHub-reviewed advisory GHSA-jjpj-p2wh-qf23 published (critical)
• 2026-02-26 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-jjpj-p2wh-qf23 github.com
2. CVE.org record CVE-2026-27495 cve.org
3. NVD entry CVE-2026-27495 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. docs.n8n.io docs.n8n.io
3. github.com github.com
4. github.com github.com
5. github.com github.com

Critical npm advisories · Today’s Security Digest