Auth bypass in Themoos Core-Moos
CVE-2026-85424
MOOS core-moos through 10.4.0 lacks authentication in the wire protocol, allowing unauthenticated clients to connect with full publish, subscribe, and database clear privileges. Attackers can bypass the compile-time protocol string check and connect with arbitrary client names to execute privileged operations including DB_CLEAR which resets all variables and clears client mail queues.
Vulnerability class: Broken Authentication
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: 0.008 (56.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.003
Affected products
Weakness classification (CWE)
References
- github.com/themoos/core-moos (Product, product)
- github.com/themoos/core-moos/blob/ec9c77c68fcbdef8f5e4c60fe243acd223433f0c/Core… (technical-description, Issue Tracking)
- github.com/themoos/core-moos/commit/5ff5cdec44242156a168cc1a545a6a21357bd3ac (Patch, patch, Issue Tracking)
- github.com/themoos/core-moos/pull/84 (issue-tracking, Patch, patch, Issue Tracking)
- www.vulncheck.com/advisories/moos-core-moos-through-10.4.0-missing-authenticati… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-85424?
- CVE-2026-85424 is a critical-severity vulnerability in Themoos Core-Moos, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-09-03.
- How severe is CVE-2026-85424?
- Critical severity. CVSS v3 base score is 9.8 out of 10.