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Advisory record · GHSA-3xr5-8w6c-p5gw

Backstage: Improper access control in backend action invocation

CVSS 4.3 MediumEPSS 0.0024 · 15th percentile

Published by the GitHub Advisory Database at 15 Oct 2026, 20:21 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
@backstage/backend-defaultsnpm<0.17.80.17.8
Identifiers
GHSA-3xr5-8w6c-p5gw · CVE-2026-106495
Weakness (CWE)
CWE-284
Tags
Published
15 Oct 2026
Updated
15 Oct 2026

Machine-written summary

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

Backstage's @backend-defaults npm package is affected in versions before 0.17.8. An authenticated user could invoke actions that an operator had excluded through action configuration, though existing action permissions and downstream authorization still apply. Upgrade @backstage/backend-defaults to version 0.17.8; until then, the source suggests limiting access to action invocation endpoints to trusted service callers.

Written 31 Oct 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
4.3 Medium 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0024, the 15th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 13:33 UTC First seen by agentprime
  2. 31 Oct 2026, 13:33 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.