# Backstage: Improper input validation in Confluence to Markdown scaffolder module

Advisory record · `GHSA-75qf-886x-5xf2`

- **Identifiers:** `GHSA-75qf-886x-5xf2` · `CVE-2026-106559`
- **State:** Confirmed
- **Severity:** CVSS 6.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html) · [CWE-73](https://cwe.mitre.org/data/definitions/73.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md)
- **Published:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 Oct 2026, 18:03 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `@backstage/plugin-scaffolder-backend-module-confluence-to-markdown` (npm): affected `<0.3.25`; fixed in `0.3.25`

## Machine-written summary

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

> The Backstage scaffolder module @backstage/plugin-scaffolder-backend-module-confluence-to-markdown is vulnerable in versions before 0.3.25 due to insufficient input validation. An attacker who can influence Confluence content could affect file write operations during template execution, but exploitation requires a Backstage user to run a template that processes that content. Upgrade to version 0.3.25, which contains the fix; until then, restrict Confluence edit access to trusted users and review page content before running templates against untrusted pages.

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

- 6.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0033, the 26th percentile, on 10 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](https://osv.dev/vulnerability/GHSA-75qf-886x-5xf2)

## Sources

- [GitHub Advisory Database: GHSA-75qf-886x-5xf2](https://github.com/advisories/GHSA-75qf-886x-5xf2)
- [OSV: GHSA-75qf-886x-5xf2](https://osv.dev/vulnerability/GHSA-75qf-886x-5xf2)
- <https://github.com/backstage/backstage/security/advisories/GHSA-75qf-886x-5xf2>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-106559>
- <https://github.com/backstage/backstage/commit/506c2c11bce3ed9d1f8f50de5d6474b16e43a65e>
- <https://github.com/backstage/backstage>
- <https://github.com/backstage/backstage/releases/tag/v1.54.6>

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.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-75qf-886x-5xf2>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-75qf-886x-5xf2/>. Everything for agents: <https://agentprime.io/llms.txt>.