Vulnerability in Peppermint-Lab Peppermint
CVE-2026-85391
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.7% 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: 0.006 · change: +0.003
Affected products
Weakness classification (CWE)
References
- github.com/Peppermint-Lab/peppermint (product)
- github.com/Peppermint-Lab/peppermint/blob/0.5.5/apps/api/src/lib/jwt.ts (technical-description)
- github.com/Peppermint-Lab/peppermint/blob/0.5.5/docker-compose.yml (technical-description)
- github.com/Peppermint-Lab/peppermint/issues/528 (issue-tracking)
- www.vulncheck.com/advisories/peppermint-through-0.5.5-use-of-hard-coded-jwt-sig… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-85391?
- CVE-2026-85391 is a critical-severity vulnerability in Peppermint-Lab Peppermint, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2026-09-03.
- How severe is CVE-2026-85391?
- Critical severity. CVSS v3 base score is 9.8 out of 10.