Critical severity · published Oct 6, 2026
CVE-2026-106486
Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
9.9
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BA
backstage · backstage
< 1.54.6 · source: vendor, NVD
PL
plugin-scaffolder-backend-module-bitbucket-cloud · @backstage
< 0.3.10 · source: vendor
PL
plugin-scaffolder-backend-module-bitbucket-server · @backstage
< 0.2.25 · source: vendor
BA
Backstage/plugin-scaffolder-backend-module-bitbucket-cloud · Linuxfoundation
before 0.3.10 · source: NVD
BA
Backstage/plugin-scaffolder-backend-module-bitbucket-server · Linuxfoundation
before 0.2.25 · source: NVD
Affected product
PL
plugin-scaffolder-backend-module-bitbucket-cloud
@backstage
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-106486
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-106486
x_refsource_CONFIRM
https://github.com/backstage/backstage/security/advisories/GHSA-g8rx-f7m5-7794
x_refsource_MISC
https://github.com/backstage/backstage/commit/818528e112c36167d76187e9e63fb518399c4dd2
x_refsource_MISC
https://github.com/backstage/backstage/releases/tag/v1.54.6
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