GHSA-rg9r-hr7g-5gc2: @backstage/plugin-techdocs-backend (CVE-2026-106489)

Package	Ecosystem	Affected	Fixed in
@backstage/plugin-techdocs-backend	npm	<2.2.4	2.2.4

Machine-written summary

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

The @backstage/plugin-techdocs-backend npm package is vulnerable in versions before 2.2.4. An authenticated user who has access to one TechDocs documentation site could craft a URL to read documentation belonging to a different entity. The issue affects only deployments that use an external TechDocs builder with external storage such as S3 or GCS and have the permission framework enabled. The source says to upgrade to version 2.2.4, which is the patched release, as no other workaround exists.

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

Score	Rating	CVSS	Vector	Source
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 0.0029, the 21st percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

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