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.
CVE-2026-44595
MEDIUMPre-NVD 4.34.3Elevated
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 4.3 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.0%, top 91% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m, epss
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 4.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.3
- EG Score
- 4.3(low)
- EPSS
- 59.4%
- KEV
- Not listed
Published
May 27, 2026
Last Modified
July 18, 2026
Advisory Details (5)
Auto-updated Jul 17, 2026🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available
Unauthorized user enumeration via IAM API endpoints · Advisory · yamcs/yamcs · GitHub
https://github.com/yamcs/yamcs/security/advisories/GHSA-p2rj-mrmc-9w29github_release Patch Available
Yamcs 5.13.0
Patch available: yamcs/yamcs yamcs-5.13.0
https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0github_release Patch Available
Yamcs 5.12.7
Patch available: yamcs/yamcs yamcs-5.12.7
https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7github_commit
commit e90099fba98e (yamcs/yamcs)
Fix landed in yamcs/yamcs commit e90099fba98e — awaiting tagged release
https://github.com/yamcs/yamcs/commit/e90099fba98e96214217c195b6a5b87b5f46e51cgithub_commit
commit 0e12b518f103 (yamcs/yamcs)
Fix landed in yamcs/yamcs commit 0e12b518f103 — awaiting tagged release
https://github.com/yamcs/yamcs/commit/0e12b518f103f24681299318a30a460fe4327b88Vendor Advisories for CVE-2026-44595(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Maven(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| org.yamcs:yamcs-core | 0.29.3 ... 5.9.9 (165 versions) | 5.12.7 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 05:52 UTCOSV refresh
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-05-27 00:14 UTCEG score recompute
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-52604First seen May 30, 2026
YAMCS yamcs-core 5.12.7 - User Enumeration
Open source ↗
Related CVEs(same CWE)
Same CWE
10 shownCWE-862
Frequently asked(5)
What is CVE-2026-44595?
CVE-2026-44595 is a medium vulnerability published on May 27, 2026. 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…
When was CVE-2026-44595 disclosed?
CVE-2026-44595 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on July 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44595 actively exploited?
CVE-2026-44595 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 59.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-44595?
CVE-2026-44595 has a CVSS v3 base score of 4.3 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-44595?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44595, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-44595
Is Your Infrastructure Affected by CVE-2026-44595?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.