CVE-2026-106459
Backstage: Improper input validation in Sentry scaffolder actions
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.5
Backstage: Improper input validation in Sentry scaffolder actions
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
- Record
CVE-2026-106459- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-200, CWE-918
- Updated
- 2026-11-02
EUVDEUVD-2026-93993
8.5
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
- Record
EUVD-2026-93993- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g734-fhp4-7mfp
8.5
Backstage: Improper input validation in Sentry scaffolder actions
Impact
An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token.
Patches
Upgrade @backstage/plugin-scaffolder-backend-module-sentry to version 0.3.8 or later. The fixed package is available in Backstage v1.54.8 and Backstage v1.55.0.
The update removes custom action-level apiBaseUrl values. Move any such value to scaffolder.sentry.apiBaseUrl before upgrading.
Workarounds
- Disable the affected actions until the patched package is deployed.
- Restrict
scaffolder.action.executepermission for the affected Sentry actions to trusted users and templates.
- Record
GHSA-g734-fhp4-7mfp- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-200, CWE-918
- Updated
- 2026-11-02
NVD
8.5
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
- Record
CVE-2026-106459- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-200, CWE-918
- Updated
- 2026-11-02
OSV
8.5
Backstage: Improper input validation in Sentry scaffolder actions
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
- Record
CVE-2026-106459- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-200, CWE-918
- Updated
- 2026-11-02
OSVGHSA-g734-fhp4-7mfp
8.5
Backstage: Improper input validation in Sentry scaffolder actions
Impact
An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token.
Patches
Upgrade @backstage/plugin-scaffolder-backend-module-sentry to version 0.3.8 or later. The fixed package is available in Backstage v1.54.8 and Backstage v1.55.0.
The update removes custom action-level apiBaseUrl values. Move any such value to scaffolder.sentry.apiBaseUrl before upgrading.
Workarounds
- Disable the affected actions until the patched package is deployed.
- Restrict
scaffolder.action.executepermission for the affected Sentry actions to trusted users and templates.
- Record
GHSA-g734-fhp4-7mfp- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-200, CWE-918
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/plugin-scaffolder-backend-module-sentrynpm |
0.3.0 up to 0.3.8 | 0.3.8 |
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-2026-106459 is a high vulnerability (CVSS 8.5) in @backstage Plugin-scaffolder-backend-module-sentry, published October 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in @backstage/plugin-scaffolder-backend-module-sentry 0.3.8.
References
github.com/backstage/backstage/security/advisories/GHSA-g734-fhp4-7mfp
github.com/backstage/backstage/commit/b0170fad7962fb8c3d71366b5265cf283c7bbcf7
github.com/backstage/backstage/releases/tag/v1.54.8
github.com/backstage/backstage/releases/tag/v1.55.0
nvd.nist.gov/vuln/detail/CVE-2026-106459
github.com/advisories/GHSA-g734-fhp4-7mfp
github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106459.json
github.com/backstage/backstage