CVE-2026-100864

heym before 0.0.91 contains a sandbox escape vulnerability in the expression engine's DotList map/filter and fallback resolver that allows authenticated users to execute arbitrary Python code. Attackers can craft workflow expressions using dunder attribute access through item expressions or the fallback resolver to access os.system and execute commands as the backend process.

  • Published Sep 27, 2026
  • CVSS 8.7 high
  • 0.7% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-100864 at the National Vulnerability Database