Answer in brief
CVE-2026-55521 records a High severity (CVSS 8.8) vulnerability in Yamcs : Multiple Missing Function Level Access Control vulnerabilities in Yamcs Core API. The current sources do not mark it as known exploited. The current feed maps yamcs/yamcs (generic), org.yamcs:yamcs-core (maven), org.yamcs:yamcs-core (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps yamcs/yamcs (generic), org.yamcs:yamcs-core (maven), org.yamcs:yamcs-core (maven). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| yamcs/yamcsgeneric | < 5.12.8 || >= 5.13.0, < 5.13.2 | Not reported |
| org.yamcs:yamcs-coremaven | >=5.13.0,<=5.13.1 | 5.13.2 |
| org.yamcs:yamcs-coremaven | <=5.12.7 | 5.12.8 |
Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs omits authorization checks in IndexesApi.listPacketIndex, IndexesApi.listEventIndex, Cop1Api.disable, Cop1Api.resume, Cop1Api.initialize, Cop1Api.updateConfig, and TimeApi.setTime. An authenticated low-privilege user can read packet and event index metadata without ObjectPrivilegeType.ReadPacket, alter COP-1 link state without SystemPrivilege.ControlLinks, and manipulate simulation time. These operations can disclose telemetry metadata, disrupt telecommand handling, and affect system integrity and availability. This issue is fixed in versions 5.12.8 and 5.13.2.
Quoted source text, attributed separately from HOL analysis.