@backstage/backend-app-api leaks GitLab access tokens

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

EPSS

• CVE-2023-6944: 0.56% estimated exploitation activity in the next 30 days; percentile 46.69 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A flaw was found in the Red Hat Developer Hub (RHDH). The catalog-import function leaks GitLab access tokens on the frontend when the base64 encoded GitLab token includes a newline at the end of the string. The sanitized error can display on the frontend, including the raw access token. Upon gaining access to this token and depending on permissions, an attacker could push malicious code to repositories, delete resources in Git, revoke or generate new keys, and sign code illegitimately.

Published by the source

4 Jan 2024, 12:30 UTC

Last modified by the source

1 Oct 2025, 20:11 UTC

Source last checked

26 Oct 2026, 12:38 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-86rg-pf4c-5grg

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-86rg-pf4c-5grg

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# Patch Next advisory brief: CVE-2023-6944

Advisory: @backstage/backend-app-api leaks GitLab access tokens
IDs: CVE-2023-6944, GHSA-86rg-pf4c-5grg
Record: https://patchnext.com/advisories/cve-2023-6944 (revision 2, source checked 26 Oct 2026, 12:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @backstage/backend-app-api 0.5.9-next.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @backstage/backend-app-api: affected < 0.5.9-next.1; fixed in 0.5.9-next.1

## Suggested inspection (read-only)
- `npm ls @backstage/backend-app-api --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @backstage/backend-app-api.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-86rg-pf4c-5grg (OSV record GHSA-86rg-pf4c-5grg lists affected ranges: npm @backstage/backend-app-api >=0 <0.5.9-next.1 (fixed))
- Verified: https://github.com/advisories/GHSA-86rg-pf4c-5grg (GitHub-reviewed advisory GHSA-86rg-pf4c-5grg lists affected ranges: npm @backstage/backend-app-api >=0 <0.5.9-next.1)

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