CVE-2026-27493
What it is
n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, a second-order expression injection vulnerability existed in n8n's Form nodes that could allow an unauthenticated attacker to inject and evaluate arbitrary n8n expressions by submitting crafted form data. When chained with an expression sandbox escape, this could escalate to remote code execution on the n8n host. The vulnerability requires a specific workflow configuration to be exploitable. First, a form node with a field interpolating a value provided by an unauthenticated user, e.g. a form submitted value. Second, the field value must begin with an `=` character, which caused n8n to treat it as an expression and triggered a double-evaluation of the field content. There is no practical reason for a workflow designer to prefix a field with `=` intentionally — the character is not rendered in the output, so the result would not match the designer's expectations. If added accidentally, it would be noticeable and very unlikely to persist. An unauthenticated attacker would need to either know about this specific circumstance on a target instance or discover a matching form by chance. Even when the preconditions are met, the expression injection alone is limited to data accessible within the n8n expression context. Escalation to remote code execution requires chaining with a separate sandbox escape vulnerability. 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. Review usage of form nodes manually for above mentioned preconditions, disable the Form node by adding `n8n-nodes-base.form` to the `NODES_EXCLUDE` environment variable, and/or disable the Form Trigger node by adding `n8n-nodes-base.formTrigger` to the `NODES_EXCLUDE` environment variable. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 1.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.4% in the next 30 days (EPSS).
- Severity: 9.5 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.4% · EPSS, next 30 days
- Weakness
- CWE-94 · Code injection
- Record status
- Analyzed
Affected
- n8n < 1.123.22
- n8n < 2.9.3
- n8n < 2.10.1
Attack profile CVSS 4.0 · 9.5
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-27493.md and follow it. Check whether this project is affected by CVE-2026-27493. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/n8n-io/n8n/commit/562d867483e871b0f1e31776252e23bd721df75b
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/security/advisories/GHSA-75g8-rv7v-32f7
References
- https://github.com/n8n-io/n8n/commit/562d867483e871b0f1e31776252e23bd721df75b
- https://github.com/n8n-io/n8n/issues/19
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/releases/tag/[email protected]
- https://github.com/n8n-io/n8n/security/advisories/GHSA-75g8-rv7v-32f7