⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 8.6

How to Fix CVE-2026-47107: Critical Vulnerability in windmill

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 8.6 - High
Actively exploited?Not currently listed in CISA KEV
Affected0 < 1.703.2
Fixed inf8467f38c8a053117ce62f96684cfb15ef792f08
Type (CWE)CWE-276: Incorrect Default Permissions

What is CVE-2026-47107?

CVE-2026-47107 is a security flaw in windmill. 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 WM_TOKEN JWTs to gain workspace-admin access to other users' workspaces.

Why this CVE matters

Unpatched network-facing software is the leading initial-access vector in public breach reporting. Treat any CVSS-9 class flaw on an internet-reachable system as urgent, regardless of whether public exploit code has been observed yet.

For deployments of windmill that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open windmill's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-47107

  1. Read the vendor advisory in full: https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
  2. Upgrade windmill to f8467f38c8a053117ce62f96684cfb15ef792f08 or a later version listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Open-source library upgrade

The vendor advisory (https://github.com/windmill-labs/windmill/commit/f8467f38c8a053117ce62f96684cfb15ef792f08) names the patched release as windmill f8467f38c8a053117ce62f96684cfb15ef792f08. Pull the

fixed version through whichever ecosystem actually ships windmill.


# Vendor advisory: https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
# npm / pnpm / yarn
npm install windmill@latest
npm ls windmill

# Or pin to the patched version named in the advisory
npm install windmill@<patched-version>

# pip / Poetry
pip install --upgrade "windmill"
pip show windmill | grep -i version
poetry add "windmill@^<patched-version>"

# Go modules
go get example.com/windmill@<patched-version>
go mod tidy

# Rust crates
cargo update -p windmill

# Composer
composer require vendor/windmill:^<patched-version>


# Vendor advisory: https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
# Container image: rebuild against the patched base and roll the deployment.
docker pull <your-registry>/windmill:<patched-tag>
docker stop <app> && docker rm <app>
docker run -d --name <app> <your-registry>/windmill:<patched-tag>

# Kubernetes
kubectl set image deployment/<deployment-name> <container>=<your-registry>/windmill:<patched-tag>
kubectl rollout status deployment/<deployment-name>

Linux package upgrade

The vendor advisory (https://github.com/windmill-labs/windmill/commit/f8467f38c8a053117ce62f96684cfb15ef792f08) names the patched build as windmill f8467f38c8a053117ce62f96684cfb15ef792f08.


# Ubuntu / Debian
sudo apt-get update
sudo apt-get install --only-upgrade bind9
dpkg -s bind9 | grep -i version

# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade --refresh bind9 -y
rpm -q bind9

# openSUSE
sudo zypper refresh && sudo zypper update bind9

# Restart the service that loads the patched binary
sudo systemctl restart bind9 2>/dev/null || true
sudo systemctl status bind9 --no-pager 2>/dev/null || true


# Vendor advisory: https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
# Container deployments: rebuild with the patched package layer, then roll the workload.
docker pull <your-registry>/bind9:<patched-tag>
docker stop <app> && docker rm <app>
docker run -d --name <app> <your-registry>/bind9:<patched-tag>

# Kubernetes
kubectl set image deployment/<deployment-name> bind9=<your-registry>/bind9:<patched-tag>
kubectl rollout status deployment/<deployment-name>

Verify the fix landed


# Vendor advisory: https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
# 1. Compare the running version against the fixed build named above.
#    (Replace the version probe with the platform-specific command from the block above.)

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag this CVE on the patched target.

# 3. Inspect recent service / kernel logs for crash loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

If you cannot patch immediately

Restrict access to the management interface to trusted internal IP addresses only. Block public access at the firewall and require VPN for any remote administration. Apply the patch as soon as a maintenance window allows.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for log entries that do not match your normal request patterns, especially repeated requests to the same uncommon endpoint, and any administrative changes you cannot tie back to a known operator.

Frequently asked questions

Is CVE-2026-47107 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-47107?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for windmill run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*