Auth bypass in Spaceapplications Yamcs
CVE-2026-44595
Yamcs is a mission control framework. Prior to 5.12.7, the IAM API endpoints listUsers, getUser, listGroups, and getGroup in yamcs-core did not enforce the required SystemPrivilege.ControlAccess check in yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java, so any authenticated user, even one with low or no privileges, could enumerate all user accounts in the system including their usernames, superuser status, and group memberships. This issue is fixed in versions 5.12.7 and 5.13.0.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.011 (64.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Spaceapplications Yamcs
- Yamcs — versions < 5.12.7
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/yamcs/yamcs/security/advisories/GHSA-p2rj-mrmc-9w29 (Exploit, Vendor Advisory)
- github.com/yamcs/yamcs/commit/0e12b518f103f24681299318a30a460fe4327b88 (Patch)
- github.com/yamcs/yamcs/commit/e90099fba98e96214217c195b6a5b87b5f46e51c (Patch)
- github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7 (Release Notes)
- github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-44595?
- CVE-2026-44595 is a medium-severity vulnerability in Spaceapplications Yamcs, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-07-16.
- How severe is CVE-2026-44595?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2026-44595 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.