Backstage is an open framework for building developer portals. From 0.3.0 until 0.6.15 and 0.7.5, the @backstage/plugin-auth-node package did not consistently honor explicit negative email verification during shared OAuth profile normalization. The affected paths include a selected profile email marked verified: false, a matching raw provider email marked email_verified: false, and an email obtained only from an ID token marked email_verified: false. Exploitation requires an admitted identity-provider user who can supply or change an unverified email and a deployment that uses the selected profile email to resolve catalog identities. The verification metadata must apply to the selected email; an absent email_verified claim alone is not affected. In an affected configuration, the user may assume another catalog identity and obtain its associated access and permissions. This issue is fixed in versions 0.6.15 and 0.7.5.
https://github.com/backstage/backstage/security/advisories/GHSA-xm5q-p7w3-x6cp
https://github.com/backstage/backstage/releases/tag/v1.54.7
https://github.com/backstage/backstage/releases/tag/v1.49.7
https://github.com/backstage/backstage/commit/fc5e30aba8ea7282ed3658c3b985cec71051cf9d
https://github.com/backstage/backstage/commit/f0a43dacd1b501064da042b43eab9c1e06371d38
https://github.com/backstage/backstage/commit/507e65ab9160aae6b602513dbfaebdd6be0ca8bb