Backstage: Explicit negative email verification can be ignored during shared OAuth profile normalization

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No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

6 Oct 2026 20:22:31 UTC

Source modified

9 Oct 2026 01:48:01 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

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.

Source published

Oct 6, 2026, 8:22:31 PM (timezone not stated)

Source modified

Oct 9, 2026, 1:48:01 AM (timezone not stated)

Observed here

30 Oct 2026 01:52:20 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

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.

Source published

6 Oct 2026 21:17:16 UTC

Source modified

27 Oct 2026 20:41:12 UTC

Observed here

29 Oct 2026 05:48:21 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

### 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.

Source published

7 Oct 2026 20:23:52 UTC

Source modified

7 Oct 2026 20:30:06 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Publisher rating · MODERATE