CVE-2026-47107: Windmill < 1.703.2 Incorrect Default Permissions in nsjail Configuration
Windmill prior to 1.703.2 contains an incorrect default permissions vulnerability in nsjail sandbox configuration files where /etc is bind-mounted without read-write restrictions, allowing authenticated users to write arbitrary entries to /etc/hosts, /etc/resolv.conf, and /etc/ssl/certs/ca-certificates.crt from within script execution sandboxes. Attackers can exploit persistent poisoned entries across all subsequent script executions on the same worker pod to redirect hostnames, intercept DNS queries, perform transparent HTTPS man-in-the-middle attacks, and intercept WMTOKEN JWTs to gain workspace-admin access to other users' workspaces.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Windmillto a version that resolves this vulnerability.Fixed in 1.703.2 - Configuration
Fix nsjail sandbox configuration so that /etc is not bind-mounted with incorrect default permissions; ensure write access from within script execution sandboxes to /etc/hosts, /etc/resolv.conf, and /etc/ssl/certs/ca-certificates.crt is prevented (read-write restrictions on the bind mount).
nsjail sandbox configuration (Windmill) /etc bind-mount permissions = read-write restricted - Configuration
Ensure the sandbox cannot write arbitrary entries to /etc/hosts from within script execution.
nsjail sandbox configuration (Windmill) /etc/hosts write access = prevent write - Configuration
Ensure the sandbox cannot write arbitrary entries to /etc/resolv.conf from within script execution.
nsjail sandbox configuration (Windmill) /etc/resolv.conf write access = prevent write - Configuration
Ensure the sandbox cannot write arbitrary entries to /etc/ssl/certs/ca-certificates.crt from within script execution.
nsjail sandbox configuration (Windmill) /etc/ssl/certs/ca-certificates.crt write access = prevent write
Event History
Frequently Asked Questions
What is the severity of CVE-2026-47107?
CVE-2026-47107 is considered a medium severity vulnerability due to incorrect default permissions allowing authenticated users to modify system files.
How do I fix CVE-2026-47107?
To fix CVE-2026-47107, upgrade Windmill to version 1.703.2 or later where the permissions issue is resolved.
Who is affected by CVE-2026-47107?
CVE-2026-47107 affects all versions of Windmill prior to 1.703.2 where nsjail configuration files have incorrect permissions.
What systems are impacted by CVE-2026-47107?
CVE-2026-47107 impacts systems running Windmill versions below 1.703.2 that utilize nsjail sandbox configurations.
What can attackers do with CVE-2026-47107?
Attackers can exploit CVE-2026-47107 to write arbitrary files on the system due to insufficient permission controls.