Security readout for executives and security teams
Plain-English summary
CVE-2026-0863 lets a low-privileged authenticated n8n user escape the Python task sandbox through the Code block and run unrestricted Python. On Internal execution mode, this may enable full n8n instance takeover. External mode, such as the official Docker sidecar model, limits execution to a sidecar container and reduces impact.
Executive priority
Prioritize remediation for n8n systems with multiple users, automation access to sensitive systems, or Internal execution mode. This is high urgency because successful exploitation can move from workflow access to code execution and possible instance takeover.
Technical view
The issue is a CWE-95 sandbox escape in n8n’s python-task-executor involving string formatting and exception handling. CVSS is 8.5 High: network reachable, low privileges, no user interaction, high complexity, changed scope, and high confidentiality, integrity, and availability impact. A patch commit is referenced, but the source bundle does not name a fixed release version.
Likely exposure
Exposure is most relevant where untrusted or broadly provisioned authenticated users can use n8n Code blocks. Internal execution mode has the highest host-impact risk. External execution mode reduces impact to the sidecar container. The affected-version data in the bundle is limited; confirm exact installed versions against vendor guidance.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Public advisories describe the vulnerability class and impact. Treat exploitability as credible for users with basic authenticated access to Code blocks, but do not assume internet-scale unauthenticated exploitation from the provided evidence.
Researcher notes
Do not infer a fixed version from the bundle; only a patch commit is cited. Validate exposure by configuration and permissions, not version alone. Internal versus External execution mode materially changes impact. No KEV or cited active-exploitation evidence is provided.
Mitigation direction
- Apply the n8n fixed release containing commit b73a4283cb14e0f27ce19692326f362c7bf3da02 when available.
- Check n8n vendor guidance for exact fixed versions and upgrade instructions.
- Restrict Code block access to trusted users until remediation is complete.
- Prefer External execution mode where operationally feasible to reduce host impact.
- Review workflows created or modified by low-privileged users.
Validation and detection
- Inventory all n8n instances, versions, and execution modes.
- Confirm whether each instance includes the referenced patch commit or vendor-fixed release.
- List users and roles with Code block permissions.
- Review recent workflow changes involving Python Code blocks.
- Verify External mode sidecar isolation where used.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-95: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-0863 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H1.86Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.5HighVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://research.jfrog.com/vulnerabilities/n8n-python-runner-sandbox-escape-jfsa-2026-001651077/CVE reference · third-party-advisory
- https://github.com/n8n-io/n8n/commit/b73a4283cb14e0f27ce19692326f362c7bf3da02CVE reference · patch
- https://www.smartkeyss.com/post/cve-2026-0863-python-sandbox-escape-in-n8n-via-exception-formatting-and-implicit-code-executionCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.