CVE-2026-29184: @backstage/plugin-scaffolder-backend: Potential Session Token Exfiltration via Log Redaction Bypass

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-07 · updated 2026-06-17
Weakness: CWE-532

Description

Backstage is an open framework for building developer portals. Prior to version 3.1.4, a malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. This issue has been patched in version 3.1.4.

Affected products

@backstage plugin-scaffolder-backend: before 3.1.4 — fixed in 3.1.4

How to fix

Upgrade to a fixed version: @backstage plugin-scaffolder-backend 3.1.4. Check the vendor advisory for mitigations.

References

https://github.com/backstage/backstage/security/advisories/GHSA-8qp7-fhr9-fw53

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