RCE in Heymrun Heym
CVE-2026-100865
Heym before 0.0.53 evaluates workflow condition expressions using Python's eval() with insufficient sandboxing in the workflow executor service. Authenticated users can edit workflow condition nodes or import malicious templates to execute arbitrary Python and OS commands as the backend process user.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (34.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-pm6h-x3h5-j38h) (vendor-advisory)
- www.vulncheck.com/advisories/heym-before-0.0.53-multiple-rce-and-authentication… (third-party-advisory)
- Patch Commit (patch)
Frequently asked questions
- What is CVE-2026-100865?
- CVE-2026-100865 is a high-severity vulnerability in Heymrun Heym, classified under Code Injection. CVSS score: 8.8/10. Published 2026-09-27.
- How severe is CVE-2026-100865?
- High severity. CVSS v3 base score is 8.8 out of 10.