CVE-2026-106486

Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions

State: Published
Severity: 8.5 High
Published: Oct 6, 2026
Updated: Oct 7, 2026
Reserved: Oct 6, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	8.5 High	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-59 Improper Link Resolution Before File Access ('Link Following')

Affected Products

Product	Versions
backstagebackstage	< 1.54.6Affected
plugin-scaffolder-backend-module-bitbucket-cloud@backstage	< 0.3.10Affected
plugin-scaffolder-backend-module-bitbucket-server@backstage	< 0.2.25Affected

References

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