High 8.5Published Oct 6, 2026

CVE-2026-106486Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions

Updated under an hour ago (2026-10-19 08:23 UTC)

Does this affect you?

It affects backstage and 2 other products. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.33%, higher than 24% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for backstage

Exploited in the last 30 days

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: 8.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-22, CWE-59
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.33% (percentile 24)
Assigned by: GitHub_M
NVD analysis: Undergoing Analysis
Record last updated: Oct 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

backstage backstage backstage:backstage (from the name)	before 1.54.6	CNA record
@backstage plugin-scaffolder-backend-module-bitbucket-cloud backstage:plugin_scaffolder_backend_module_bitbucket_cloud (from the name)	before 0.3.10	CNA record
@backstage plugin-scaffolder-backend-module-bitbucket-server backstage:plugin_scaffolder_backend_module_bitbucket_server (from the name)	before 0.2.25	CNA record

References

https://github.com/backstage/backstage/security/advisories/GHSA-g8rx-f7m5-7794x-refsource-confirm
https://github.com/backstage/backstage/commit/818528e112c36167d76187e9e63fb518399c4dd2x-refsource-misc
https://github.com/backstage/backstage/releases/tag/v1.54.6x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.