n8n: Authorization bypass in Data Tables via crafted workflow ID
Summary
n8n accepts a client-supplied workflow ID and caches each workflow's owner project in memory by that ID. A crafted ID such as __proto__ causes the Data Table project check to match every project (CWE-1321, prototype pollution). An authenticated member who can create and run workflows can list, read, modify and delete Data Table rows in all projects of the instance.
Affected
- n8n 2.44.0 before 2.44.1
- n8n before 2.43.5
- The n8n 1.x line is not listed as affected.
Fixed in
- n8n 2.43.5 (stable)
- n8n 2.44.1 (beta)
- Cloud instances are patched automatically according to the vendor.
Workaround
- The vendor lists temporary mitigations only, which do not fully remediate the risk:
- Restrict instance access to fully trusted users.
- Audit existing workflows for a stored ID of __proto__ and remove them.
- Disable the Data Tables module if it is not required.
- No configuration-based mitigation is documented beyond these.
Exploitation
- No evidence of exploitation in the wild found.
- Not listed in the CISA KEV catalog according to third-party mirrors (not directly verified on cisa.gov).
- CISA SSVC: exploitation none, not automatable.
- Public proof of concept: conflicting or unconfirmed.
Our recommendation
- Identify all n8n instances (self-hosted, Docker, cloud) and their versions.
- Upgrade self-hosted 2.x installations to 2.43.5 or 2.44.1 or later. Back up the data volume first, because migrations run on start.
- Apply the full October 2026 n8n release, which also contains other High advisories.
- Review and reduce accounts that can create and run workflows.
- Restrict internet exposure of the instance if it is not required.
- Review Data Table contents for sensitive data and check access logs for unexpected cross-project reads or changes if the instance was vulnerable. Assess data protection obligations where relevant.
- Note: GitHub rates the advisory 7.2, while CVSS 4.0 from NVD/VulnCheck is 8.7.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-wvjj-qg37-pv73 github.com
- VulnCheck advisory www.vulncheck.com
- n8n community security update, 14 October 2026 community.n8n.io
- CVE-2026-118649 threatint record cve.threatint.com
- TheHackerWire CVE-2026-118649 www.thehackerwire.com
- ReadTheManual: n8n patches eight self-hosted vulnerabilities readthemanual.co.uk
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 23:46.
Original description (NVD)
n8n before 2.43.5 and 2.44.x before 2.44.1 accepts a client-supplied workflow ID and caches each workflow's owner project in memory by that ID, so a crafted ID such as __proto__ makes the Data Table project check match every project. An authenticated member who can create and run workflows can list, read, modify, and delete Data Table rows in all projects of the instance.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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