CVE-2026-85391: Peppermint-Lab Peppermint

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

Peppermint through 0.5.5 contains a hardcoded JWT signing secret in docker-compose.yml that allows unauthenticated attackers to forge session tokens for any account. Attackers can use the published secret to mint valid tokens for arbitrary user IDs and access protected endpoints without credentials.

Affected products

• Peppermint-Lab Peppermint: up to and including 0.5.5

Published 2026-09-03. Last modified 2026-09-09.