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Advisory record · GHSA-fwww-cp23-7f5g

Yamcs's WebSocket subscription handlers omit the privilege checks their REST siblings enforce

CVSS 6.5 MediumEPSS 0.0045 · 39th percentile

Published by the GitHub Advisory Database at 28 Aug 2026, 17:10 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
org.yamcs:yamcs-coreMaven<5.12.8 || >=5.13.0, <5.13.25.12.8, 5.13.2
Identifiers
GHSA-fwww-cp23-7f5g · CVE-2026-55545
Weakness (CWE)
CWE-862
Tags
Published
28 Aug 2026
Updated
28 Aug 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Yamcs versions below 5.12.8 and from 5.13.0 before 5.13.2 (Maven package org.yamcs:yamcs-core) have WebSocket subscription handlers for packets, algorithm-status and mdb-changes that skip the privilege checks their REST counterparts enforce. A user with a valid account can subscribe over WebSocket and receive data that the REST API would have restricted or denied, such as raw packet data for a narrow packet-read scope. Upgrade to version 5.12.8 or 5.13.2.

Written 2 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
6.5 Medium 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0045, the 39th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:19 UTC First seen by agentprime
  2. 31 Oct 2026, 14:19 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.