CVE-2026-55545Yamcs: WebSocket subscription handlers omit the privilege checks their REST siblings enforce
- 6.5MediumCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs WebSocket subscription handlers fail to enforce the privileges required by equivalent REST endpoints. PacketsApi.subscribePackets exposes the packets WebSocket topic without ObjectPrivilegeType.ReadPacket, ProcessingApi.subscribeAlgorithmStatus exposes the algorithm-status WebSocket topic without ObjectPrivilegeType.ReadAlgorithm, and MdbOverrideApi.subscribeMdbChanges exposes the mdb-changes WebSocket topic without SystemPrivilege.GetMissionDatabase. A low-privilege authenticated user can receive telemetry packets, algorithm status, and mission database change information outside the assigned authorization scope. This issue is fixed in versions 5.12.8 and 5.13.2.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.yamcs:yamcs-coreGHSA-fwww-cp23-7f5g (opens in a new tab)
References
References5
- https://github.com/yamcs/yamcs/security/advisories/GHSA-fwww-cp23-7f5g (opens in a new tab)x_refsource_CONFIRM
- https://github.com/yamcs/yamcs/commit/0691731846c5a0aca81b88fabbd2cd51d56fe076 (opens in a new tab)x_refsource_MISC
- https://github.com/yamcs/yamcs/commit/12864af555e6ca4941b01c1f1217859cc0492ce0 (opens in a new tab)x_refsource_MISC
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8 (opens in a new tab)x_refsource_MISC
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-67839 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fwww-cp23-7f5g (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55545)Record last updated .