CVE-2026-55521

high

Description

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.

References

https://github.com/yamcs/yamcs/security/advisories/GHSA-962x-ccwf-8x6p

https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2

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

https://github.com/yamcs/yamcs/commit/493563679f838b86f3cdc5da9451d4a050ff6bd9

https://github.com/yamcs/yamcs/commit/405139afa6094dfaf63ac17f32df1f808846c950

Details

Source: Mitre, NVD

Published: 2026-08-28

Updated: 2026-09-08

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.8

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00361