Description
Improper Authentication vulnerability in Google sign-in and email confirmation in nerves-hub nerves_hub_web allows an attacker who registers another person's email address to share that person's account once they sign in. NervesHub.Accounts.update_or_create_user_from_ueberauth/1 signs a Google user in to any account carrying the same email that is not yet linked to a Google account, links it and marks the email confirmed, without the account's owner ever having proved they own the address. NervesHubWeb.SessionController.confirm/2 likewise signs in whoever follows a confirmation link. An attacker registers the address from the sign-up form, changes their own account's email to it, or registers it as an organization admin from an invite link, and keeps the password; when the address's owner signs in with Google or follows the confirmation link, they land in that account.

The Google path also creates accounts with registrations closed and never checks Google's email_verified claim, and the API's password sign-in in NervesHubWeb.API.UserController issues tokens to accounts whose email was never confirmed. The attacker gains only what the victim is granted afterwards, and nothing on accounts whose owners never use either path.

This issue affects nerves_hub: from 2.3.0 before 2.5.3.
Published: 2026-11-10
Score: 7.4 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Solution

Upgrading does not undo links already made. Review the users rows that carry both a password_hash and a google_id; most are one person signing in both ways, but an account registered for someone else's address was usually created well before its first Google sign-in, so compare inserted_at with google_last_synced_at. For one its owner did not set up, set its google_id to NULL, delete its user_tokens rows to end its sessions and revoke its API tokens, and have the address's owner reset the password. An account taken through a confirmation link looks the same as one its owner set up; its owner can end anyone else's access by resetting the password, which ends every session and revokes every API token. Before upgrading, check how your instance lets people sign up: SIGN_UP_METHODS replaces OPEN_FOR_REGISTRATIONS, and instances that relied on Google sign-in to create accounts while registrations were off need SIGN_UP_METHODS=google.


Vendor Workaround

Turn off Google sign-in by unsetting GOOGLE_CLIENT_ID until the upgrade; users who only sign in with Google cannot sign in while it is off. This does not close the confirmation link path. Turning off registrations stops strangers using the sign-up form, but not an organization admin registering from an invite link.

Tracking

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Advisories

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History

Tue, 10 Nov 2026 11:00:00 +0000

Type Values Removed Values Added
Description Improper Authentication vulnerability in Google sign-in and email confirmation in nerves-hub nerves_hub_web allows an attacker who registers another person's email address to share that person's account once they sign in. NervesHub.Accounts.update_or_create_user_from_ueberauth/1 signs a Google user in to any account carrying the same email that is not yet linked to a Google account, links it and marks the email confirmed, without the account's owner ever having proved they own the address. NervesHubWeb.SessionController.confirm/2 likewise signs in whoever follows a confirmation link. An attacker registers the address from the sign-up form, changes their own account's email to it, or registers it as an organization admin from an invite link, and keeps the password; when the address's owner signs in with Google or follows the confirmation link, they land in that account. The Google path also creates accounts with registrations closed and never checks Google's email_verified claim, and the API's password sign-in in NervesHubWeb.API.UserController issues tokens to accounts whose email was never confirmed. The attacker gains only what the victim is granted afterwards, and nothing on accounts whose owners never use either path. This issue affects nerves_hub: from 2.3.0 before 2.5.3.
Title Improper authentication lets Google sign-in and confirmation links sign users in to accounts registered with their email address by someone else
First Time appeared Nerves-hub
Nerves-hub nerves Hub Web
Weaknesses CWE-287
CWE-345
CPEs cpe:2.3:a:nerves-hub:nerves_hub_web:*:*:*:*:*:*:*:*
Vendors & Products Nerves-hub
Nerves-hub nerves Hub Web
References
Metrics cvssV4_0

{'score': 7.4, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

Nerves-hub Nerves Hub Web
cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-11-10T10:43:38.941Z

Reserved: 2026-11-09T22:47:57.298Z

Link: CVE-2026-120999

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-10T11:16:42.800

Modified: 2026-11-10T11:16:42.800

Link: CVE-2026-120999

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-287

    Improper Authentication

  • CWE-345

    Insufficient Verification of Data Authenticity