CVE-2026-106498: Backstage catalog entity placeholder URL validation bypass

CVE-2026-106498 · Severity: high · CVSS 7.7 · Published 2026-10-06

Backstage is an open-source framework for building internal developer portals where teams manage software catalogs and component metadata. An authenticated user could craft malicious catalog entries with placeholder directives that bypass URL validation, potentially exposing data from sources outside the intended repository that they should not have access to.

Technologies: Backstage Plugin-Catalog-Backend, @backstage/plugin-catalog-backend (npm). Vendors: Backstage, npm.

Quick answers

Is CVE-2026-106498 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-106498 being exploited in the wild.
How severe is CVE-2026-106498?
High severity, with a CVSS score of 7.7, published 6 October 2026.
Which products and versions are affected?
Backstage Plugin-Catalog-Backend before 3.5.1, 3.6.2, 3.7.2, 3.8.2, 3.9.1; @backstage/plugin-catalog-backend (npm) < 3.9.1, SEMVER:introduced=0,fixed=3.9.1.
Is there a fix for CVE-2026-106498?
Yes. @backstage/plugin-catalog-backend (npm): upgrade to 3.9.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-106498 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-106498?
Check whether you run Backstage Plugin-Catalog-Backend or @backstage/plugin-catalog-backend (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • @backstage/plugin-catalog-backend (npm): upgrade to 3.9.1 or later
    npm install @backstage/plugin-catalog-backend@3.9.1

Technical details

The @backstage/plugin-catalog-backend package improperly validates URLs in catalog entity placeholder resolution, allowing authenticated attackers to craft malicious catalog entities that reference resources outside the entity's source repository. The vulnerability exists in the placeholder directive processing logic and requires authentication; exploitation leads to unauthorized data exposure depending on system configuration.

Affected products

  • Backstage plugin-catalog-backend before 3.5.1, 3.6.2, 3.7.2, 3.8.2, 3.9.1

Identifiers

  • CVE-2026-106498
  • GHSA-qgvj-qcf8-xq73

Timeline

  • 2026-10-06: disclosed

References

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