CVE-2026-55547

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 83% 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: epss, secondary
Elevated
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs omits SystemPrivilege.ControlAccess checks from IamApi.listRoles, IamApi.getRole, and IamApi.listPrivileges in yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java. Any authenticated account can call GET /api/roles, GET /api/roles/{name}, and GET /api/privileges to enumerate available system privileges and configured role mappings. The disclosure reveals security configuration that can support targeted privilege-escalation attempts. This issue is fixed in versions 5.12.8 and 5.13.2.

CVSS v3
4.3
EG Score
4.3(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
17%
KEV
Not listed

Published

August 28, 2026

Last Modified

September 8, 2026

Advisory Details (5)

Auto-updated Aug 28, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Missing Authorization on Role and Privilege Enumeration Endpoints Allows Any Authenticated User to Disclose Full Security Configuration · Advisory · yamcs/yamcs · GitHub

https://github.com/yamcs/yamcs/security/advisories/GHSA-cvw4-55pp-3hfq
github_release Patch Available

Yamcs 5.13.2

Patch available: yamcs/yamcs yamcs-5.13.2

https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2
github_release Patch Available

Yamcs 5.12.8

Patch available: yamcs/yamcs yamcs-5.12.8

https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8
github_commit

commit dcaec5f0b2f4 (yamcs/yamcs)

Fix landed in yamcs/yamcs commit dcaec5f0b2f4 — awaiting tagged release

https://github.com/yamcs/yamcs/commit/dcaec5f0b2f4231b8e313e94d79a937169c9e0ba
github_commit

commit c2aec1c242e6 (yamcs/yamcs)

Fix landed in yamcs/yamcs commit c2aec1c242e6 — awaiting tagged release

https://github.com/yamcs/yamcs/commit/c2aec1c242e656e48b52c7f87deea88183bb592d

Vendor Advisories for CVE-2026-55547(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)
PackageVulnerable rangeFixed inDependents
org.yamcs:yamcs-core0.29.3 ... 5.9.9 (166 versions)5.12.8—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 38× 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.

  1. 2026-09-19 04:25 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 06:01 UTCEG score recompute
  4. 2026-09-17 19:31 UTCEPSS rescore
  5. 2026-09-17 07:36 UTCEG score recompute
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 09:11 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-15 10:08 UTCEG score recompute
  10. 2026-09-15 03:11 UTCEPSS rescore
  11. 2026-09-14 11:42 UTCEG score recompute
  12. 2026-09-13 16:47 UTCEPSS rescore
  13. 2026-09-13 13:17 UTCEG score recompute
  14. 2026-09-11 16:27 UTCEG score recompute
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-10 18:02 UTCEG score recompute
  17. 2026-09-10 09:35 UTCEPSS rescore
  18. 2026-09-09 19:37 UTCEG score recompute
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-08 05:37 UTCEG score recompute
  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-07 07:09 UTCEG score recompute
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-06 08:43 UTCEG score recompute
  25. 2026-09-05 10:18 UTCEG score recompute
Show 13 more
  1. 2026-09-04 11:51 UTCEG score recompute
  2. 2026-09-04 05:06 UTCEPSS rescore
  3. 2026-09-02 15:01 UTCEG score recompute
  4. 2026-09-02 14:12 UTCEPSS rescore
  5. 2026-09-01 16:29 UTCEG score recompute
  6. 2026-09-01 13:54 UTCEPSS rescore
  7. 2026-08-30 19:38 UTCEG score recompute
  8. 2026-08-30 19:17 UTCEPSS rescore
  9. 2026-08-30 01:22 UTCEPSS rescore
  10. 2026-08-28 22:48 UTCEG score recompute
  11. 2026-08-28 22:09 UTCEG score recompute
  12. 2026-08-28 20:25 UTCEG score recompute
  13. 2026-08-28 18:11 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55547?
CVE-2026-55547 is a medium vulnerability published on August 28, 2026. Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs omits SystemPrivilege.ControlAccess checks from IamApi.listRoles, IamApi.getRole, and IamApi.listPrivileges in yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java. Any authenticated account can call GET /api/roles, GET…
When was CVE-2026-55547 disclosed?
CVE-2026-55547 was first published in the National Vulnerability Database on August 28, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55547 actively exploited?
CVE-2026-55547 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55547?
CVE-2026-55547 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-55547?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55547, 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-2026-55547

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