RCE in Windmill

CVE-2026-33881

Windmill is an open-source developer platform for internal code: APIs, background jobs, workflows and UIs. Workspace environment variable values are interpolated into JavaScript string literals without escaping single quotes in the NativeTS executor. A workspace admin who sets a custom environment variable with a value containing `'` can inject arbitrary JavaScript that executes inside every NativeTS script in that workspace. This is a code injection bug in `worker.rs`, not related to the sandbox/NSJAIL topic. Version 1.664.0 patches the issue.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (31.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.7% 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-2026-33881: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33881?
CVE-2026-33881 is a high-severity vulnerability in Windmill, classified under Code Injection. CVSS score: 7.2/10. Published 2026-03-27.
How severe is CVE-2026-33881?
High severity. CVSS v3 base score is 7.2 out of 10.