CVE-2026-26964: Windmill is an open-source developer platform for internal code: APIs, background jobs, workflows and UIs. Versions 1.634.6 and below allow non-admin...

Description

Windmill is an open-source developer platform for internal code: APIs, background jobs, workflows and UIs. Versions 1.634.6 and below allow non-admin users to obtain Slack OAuth client secrets, which should only be accessible to workspace administrators. The GET /api/w/{workspace}/workspaces/get_settings endpoint returns the slack_oauth_client_secret to any authenticated workspace member, regardless of their admin status. It is expected behavior for non-admin users see a redacted version of workspace settings, as some of them are necessary for the frontend to behave correctly even for non-admins. However, the Slack configuration should not be visible to non-admins. This is a legacy issue where the setting was stored as a plain value instead of using $variable indirection, and it was never added to the redaction logic. This issue has been fixed in version 1.635.0.

Metrics

CVSS 3.1

2.7/10

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.27%

19.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Windmill	Windmill	< 1.635.0

References

https://github.com/windmill-labs/windmill/commit/43218c62852490d0efafa8f94385bfe0e8f2ad82Patch
https://github.com/windmill-labs/windmill/releases/tag/v1.635.0Product, Release Notes
https://github.com/windmill-labs/windmill/security/advisories/GHSA-f27g-j463-q85wExploit, Vendor Advisory

Timeline

Published: Feb 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-26964?

Windmill is an open-source developer platform for internal code: APIs, background jobs, workflows and UIs. Versions 1.634.6 and below allow non-admin users to obtain Slack OAuth client secrets, which should only be accessible to workspace administrators. The GET /api/w/{workspace}/workspaces/get_settings endpoint returns the slack_oauth_client_secret to any authenticated workspace member, regardless of their admin status. It is expected behavior for non-admin users see a redacted version of workspace settings, as some of them are necessary for the frontend to behave correctly even for non-admins. However, the Slack configuration should not be visible to non-admins. This is a legacy issue where the setting was stored as a plain value instead of using $variable indirection, and it was never added to the redaction logic. This issue has been fixed in version 1.635.0.

How severe is CVE-2026-26964?

CVE-2026-26964 has a CVSS score of 2.7/10 (LOW severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2026-26964?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.