CVE-2026-29184
@backstage/plugin-scaffolder-backend: Potential Session Token Exfiltration via Log Redaction Bypass
Backstage is an open framework for building developer portals. Prior to version 3.1.4, a malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. This issue has been patched in version 3.1.4.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
@backstage/plugin-scaffolder-backend: Potential Session Token Exfiltration via Log Redaction Bypass
Backstage is an open framework for building developer portals. Prior to version 3.1.4, a malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. This issue has been patched in version 3.1.4.
- Record
CVE-2026-29184- CVSS 3.1
- 2.0 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N - Weakness
- CWE-532
- Updated
- 2026-11-02
EUVDEUVD-2026-10144
Backstage is an open framework for building developer portals. Prior to version 3.1.4, a malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. This issue has been patched in version 3.1.4.
- Record
EUVD-2026-10144- CVSS 3.1
- 2.0 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8qp7-fhr9-fw53
@backstage/plugin-scaffolder-backend Vulnerable to Potential Session Token Exfiltration via Log Redaction Bypass
Impact
A malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs.
The attack requires:
- The ability to register a template in the catalog
- A victim who executes the malicious template
Patches
Patched in @backstage/plugin-scaffolder-backend version 3.1.4
Workarounds
- Implement a custom permission policy that restricts scaffolder.task.read so users can only read their own task logs
- Restrict who can register templates in the catalog to trusted users only
Resources
- Backstage Scaffolder permissions documentation: https://backstage.io/docs/permissions/plugin-authors/01-setup/
- Backstage Threat Model: https://backstage.io/docs/overview/threat-model/
- Record
GHSA-8qp7-fhr9-fw53- CVSS 3.1
- 2.0 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N - Weakness
- CWE-532
- Updated
- 2026-11-02
NVD
Backstage is an open framework for building developer portals. Prior to version 3.1.4, a malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. This issue has been patched in version 3.1.4.
- Record
CVE-2026-29184- CVSS 3.1
- 2.0 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-532
- Updated
- 2026-11-02
OSVGHSA-8qp7-fhr9-fw53
@backstage/plugin-scaffolder-backend Vulnerable to Potential Session Token Exfiltration via Log Redaction Bypass
Impact
A malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs.
The attack requires:
- The ability to register a template in the catalog
- A victim who executes the malicious template
Patches
Patched in @backstage/plugin-scaffolder-backend version 3.1.4
Workarounds
- Implement a custom permission policy that restricts scaffolder.task.read so users can only read their own task logs
- Restrict who can register templates in the catalog to trusted users only
Resources
- Backstage Scaffolder permissions documentation: https://backstage.io/docs/permissions/plugin-authors/01-setup/
- Backstage Threat Model: https://backstage.io/docs/overview/threat-model/
- Record
GHSA-8qp7-fhr9-fw53- CVSS 3.1
- 2.0 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N - Weakness
- CWE-532
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/plugin-scaffolder-backendnpm |
through 3.1.3 | 3.1.4 |
@backstage/plugin-scaffolder-backendnpm |
before 3.1.4 | 3.1.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-29184 is a low vulnerability (CVSS 2.0) in Backstage, published March 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.30%, the 23rd percentile. Fixed in @backstage/plugin-scaffolder-backend 3.1.4.