Information disclosure in Windmill

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.

Vulnerability class: Information Disclosure

Published · last modified .

CVSS v3 metric

CVSS v3 base score 2.7 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (21.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 21.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-26964: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-26964?
CVE-2026-26964 is a low-severity vulnerability in Windmill, classified under Information Disclosure. CVSS score: 2.7/10. Published 2026-02-20.
How severe is CVE-2026-26964?
Low severity. CVSS v3 base score is 2.7 out of 10.