CVE-2026-106460
mediumpriority · track · 0EPSS 0.003 · 24 %ileUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (5)
Products and version ranges known to be affected.
- linuxfoundation backstage/plugin-auth-node0.3.0 → 0.6.15nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-auth-node:*:*:*:*:*:*:*:*
- linuxfoundation backstage/plugin-auth-node0.7.0 → 0.7.5nvdUScpe:2.3:a:linuxfoundation:backstage\/plugin-auth-node:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-xm5q-p7w3-x6cpBackstage: Explicit negative email verification can be ignored during shared OAuth profile normalization2026-10-07ghsa · osvUS
### Impact Several Passport-based authentication providers use shared OAuth profile normalization from `@backstage/plugin-auth-node`. Affected versions may pass an email to email-based sign-in resolvers even when verification metadata supplied for that same address is explicitly negative. The ID-token-only fallback likewise did not consistently respect `email_verified: false`. Exploitation requires a deployment where an admitted identity-provider user can supply or change an email address without verification and Backstage uses that profile email to resolve catalog identities. In that configuration, the user may be able to assume another catalog identity and obtain its associated access and permissions. An absent `email_verified` claim is not by itself considered an affected condition. Some providers rely on authoritative organizational provisioning and intentionally omit the optional claim. Operators using email-based sign-in resolution must ensure that the configured provider restricts sign-in to the intended user population and supplies an authoritative email address, either through provider verification or trusted immutable provisioning. This advisory covers the shared Passport profile normalization path when the selected profile email itself carries `verified: false`, when a matching raw provider email carries `email_verified: false`, or when an email obtained only from an ID token carries `email_verified: false`. It does not apply verification metadata from a different address or from a separate ID token to an independently fetched provider-profile email. The generic OIDC provider follows a separate profile transform and is covered by [GHSA-826h-28h9-65hg](https://github.com/backstage/backstage/security/advisories/GHSA-826h-28h9-65hg). The two advisories are complementary; deployments using both affected paths should apply both package updates. VMware Cloud uses a separate custom token transformation and is not changed by this patch. ### Patches Fixed in `@backstage/plugin-auth-node` versions `0.6.15` and `0.7.5`. Users remaining on the `0.6.x` line should upgrade to at least `0.6.15`; users on `0.7.x` should upgrade to at least `0.7.5`. The patched packages were released with [Backstage v1.49.7](https://github.com/backstage/backstage/releases/tag/v1.49.7) and [Backstage v1.54.7](https://github.com/backstage/backstage/releases/tag/v1.54.7), respectively. The fix is also present on `master` in [commit 507e65a](https://github.com/backstage/backstage/commit/507e65ab9160aae6b602513dbfaebdd6be0ca8bb). ### Workarounds - Require the identity provider to verify user-controlled email addresses before allowing sign-in. - Ensure profile emails are immutable and provisioned from a trusted organizational source. - Use a sign-in resolver that does not depend on the profile email. - Use a custom profile transform that omits an email when matching provider metadata explicitly marks it as unverified.
sources
Which sources assert this record, and when.
references (6) nvd
External citations — patches, advisories, analysis.
- https://github.com/backstage/backstage/commit/507e65ab9160aae6b602513dbfaebdd6be0ca8bbPatch
- https://github.com/backstage/backstage/commit/f0a43dacd1b501064da042b43eab9c1e06371d38Patch
- https://github.com/backstage/backstage/commit/fc5e30aba8ea7282ed3658c3b985cec71051cf9dPatch
- https://github.com/backstage/backstage/releases/tag/v1.49.7PatchRelease Notes
- https://github.com/backstage/backstage/releases/tag/v1.54.7PatchRelease Notes
- https://github.com/backstage/backstage/security/advisories/GHSA-xm5q-p7w3-x6cpMitigationPatchVendor Advisory
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