CVE-2026-106506 backstage CVE debrief

Who should care

Backstage administrators and users with scaffolder task permissions should assess exposure and prioritize updating to version 4.1.0 or later. They should also restrict scaffolder task permissions to minimize potential exposure and monitor for unusual activity related to scaffolder tasks.

Why it matters

CVE-2026-106506 is a medium-severity vulnerability in Backstage plugin-scaffolder-backend that allows authenticated users to potentially infer confidential task data. Defenders should prioritize updating to version 4.1.0 or later, restrict scaffolder task permissions, and monitor for unusual activity.

• Authenticated users may infer confidential task data
• Requires retained task secrets and visibility of a target task

Technical summary

The @backstage/plugin-scaffolder-backend package prior to version 4.1.0 is affected by improper input validation in scaffolder task list ordering. An authenticated Backstage user with permission to create and read relevant scaffolder tasks may be able to infer confidential task data under specific conditions. This vulnerability has a medium severity and a CVSS score of 5.3. The issue is fixed in version 4.1.0, and defenders should prioritize updating to this version or later. The vulnerability requires retained task secrets, visibility of a target task, knowledge of the secret structure, and repeated requests for successful exploitation.

Defensive priority

Medium priority for Backstage users with scaffolder task permissions

Recommended defensive actions

• Review and update Backstage plugin-scaffolder-backend to version 4.1.0 or later
• Restrict scaffolder task permissions to minimize potential exposure
• Monitor for unusual activity related to scaffolder tasks
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability and its fix. However, additional information on potential exploitation or impact is limited. Defenders should verify the affected scope, review official advisories, and monitor for unusual activity related to scaffolder tasks. The vulnerability has a CVSS score of 5.3 and a medium severity. There are no known exploits or ransomware campaigns using this vulnerability.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.