CVE-2026-106486: @backstage/plugin scaffolder backend module bitbucket cloud Backstage Has IImproper Filesystem Validation Vulnerability
HIGHCVE-2026-106486 is a HIGH (CVSS 8.5) backstage has iimproper filesystem validation vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting @backstage/plugin scaffolder backend module bitbucket cloud libraries in the npm ecosystem. The issue involves backstage has iimproper filesystem validation in bitbucket pull-request scaffolder actions. Remediation is available by upgrading affected packages to version 0.3.10, 0.2.25.
CVE-2026-106486 at a Glance
Security Impact
CVSS: 8.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H).
How to Fix CVE-2026-106486
To remediate this vulnerability, upgrade all affected @backstage/plugin scaffolder backend module bitbucket cloud dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install @backstage/plugin-scaffolder-backend-module-bitbucket-cloud@0.3.10npm install @backstage/plugin-scaffolder-backend-module-bitbucket-server@0.2.25Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls @backstage/plugin-scaffolder-backend-module-bitbucket-cloudHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-106486, inspect your project dependencies using npm:
npm ls @backstage/plugin-scaffolder-backend-module-bitbucket-cloudAnalyze the terminal output to locate any version of @backstage/plugin scaffolder backend module bitbucket cloud in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.10), your application is affected.
Note: The npm ls @backstage/plugin-scaffolder-backend-module-bitbucket-cloud command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. In @backstage/plugin scaffolder backend module bitbucket cloud, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-106486 Affected @backstage/plugin scaffolder backend module bitbucket cloud Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
@backstage/plugin-scaffolder-backend-module-bitbucket-cloud
|
npm |
< 0.3.10
|
0.3.10
|
|
@backstage/plugin-scaffolder-backend-module-bitbucket-server
|
npm |
< 0.2.25
|
0.2.25
|
References
Frequently Asked Questions
What is CVE-2026-106486?
Which @backstage/plugin scaffolder backend module bitbucket cloud versions are affected?
What version fixes CVE-2026-106486?
Is @backstage/plugin-scaffolder-backend-module-bitbucket-cloud affected?
Is @backstage/plugin-scaffolder-backend-module-bitbucket-server affected?
What is the CVSS score of CVE-2026-106486?
What CWE is associated with CVE-2026-106486?
How can I check npm dependencies for CVE-2026-106486?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-g8rx-f7m5-7794",
"modified" : "2026-10-07T18:01:26Z",
"published" : "2026-10-07T18:01:26Z",
"aliases" : [ "CVE-2026-106486" ],
"summary" : "Backstage has iImproper filesystem validation in Bitbucket pull-request scaffolder actions",
"details" : "### Impact\n\nAn 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.\n\n### Patches\n\n- `@backstage/plugin-scaffolder-backend-module-bitbucket-cloud` version `0.3.10`\n- `@backstage/plugin-scaffolder-backend-module-bitbucket-server` version `0.2.25`\n\n### Workarounds\n\n- Restrict execution of affected Scaffolder templates to trusted users.\n- Avoid templates that accept user-controlled target repositories for these actions.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "@backstage/plugin-scaffolder-backend-module-bitbucket-cloud"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.3.10"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "@backstage/plugin-scaffolder-backend-module-bitbucket-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.2.25"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/backstage/backstage/security/advisories/GHSA-g8rx-f7m5-7794"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-106486"
}, {
"type" : "WEB",
"url" : "https://github.com/backstage/backstage/commit/818528e112c36167d76187e9e63fb518399c4dd2"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/backstage/backstage"
}, {
"type" : "WEB",
"url" : "https://github.com/backstage/backstage/releases/tag/v1.54.6"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-22", "CWE-59" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-10-07T18:01:26Z",
"nvd_published_at" : "2026-10-06T21:17:17Z"
}
}