CVE-2026-106486
Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
- Record
CVE-2026-106486- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22, CWE-59
- Updated
- 2026-11-02
EUVDEUVD-2026-94003
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
- Record
EUVD-2026-94003- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g8rx-f7m5-7794
Backstage has iImproper filesystem validation in Bitbucket pull-request scaffolder actions
Impact
An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect filesystem paths outside the expected working area. Depending on the backend deployment, this could compromise backend confidentiality, integrity, or availability.
Patches
@backstage/plugin-scaffolder-backend-module-bitbucket-cloudversion0.3.10@backstage/plugin-scaffolder-backend-module-bitbucket-serverversion0.2.25
Workarounds
- Restrict execution of affected Scaffolder templates to trusted users.
- Avoid templates that accept user-controlled target repositories for these actions.
- Record
GHSA-g8rx-f7m5-7794- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22, CWE-59
- Updated
- 2026-11-02
NVD
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
- Record
CVE-2026-106486- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22, CWE-59
- Updated
- 2026-11-02
OSV
Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
- Record
CVE-2026-106486- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22, CWE-59
- Updated
- 2026-11-02
OSVGHSA-g8rx-f7m5-7794
Backstage has iImproper filesystem validation in Bitbucket pull-request scaffolder actions
Impact
An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect filesystem paths outside the expected working area. Depending on the backend deployment, this could compromise backend confidentiality, integrity, or availability.
Patches
@backstage/plugin-scaffolder-backend-module-bitbucket-cloudversion0.3.10@backstage/plugin-scaffolder-backend-module-bitbucket-serverversion0.2.25
Workarounds
- Restrict execution of affected Scaffolder templates to trusted users.
- Avoid templates that accept user-controlled target repositories for these actions.
- Record
GHSA-g8rx-f7m5-7794- CVSS 3.1
- 8.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22, CWE-59
- Updated
- 2026-11-02
Affected products
- @backstage plugin-scaffolder-backend-module-bitbucket-cloud
- @backstage plugin-scaffolder-backend-module-bitbucket-server
- backstage
- linuxfoundation backstage
- linuxfoundation backstage\/plugin-scaffolder-backend-module-bitbucket-cloud
- linuxfoundation backstage\/plugin-scaffolder-backend-module-bitbucket-server
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/plugin-scaffolder-backend-module-bitbucket-cloudnpm |
before 0.3.10 | 0.3.10 |
@backstage/plugin-scaffolder-backend-module-bitbucket-servernpm |
before 0.2.25 | 0.2.25 |
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-2026-106486 is a high vulnerability (CVSS 8.5) in @backstage Plugin-scaffolder-backend-module-bitbucket-cloud, published October 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. Fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10.
References
github.com/backstage/backstage/security/advisories/GHSA-g8rx-f7m5-7794
nvd.nist.gov/vuln/detail/CVE-2026-106486