2FAuth: Missing Authorization on Share Recipients Endpoint Allows Cross-User Account Enumeration

published 2026-11-06 2 d ago modified 2026-11-06 2 d ago also EUVD-2026-118488

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits: 0; none known

2FAuth is a web app to manage Two-Factor Authentication (2FA) accounts and generate their security codes. Prior to 8.0.0, the recipients() method in app/Api/v1/Controllers/TwoFAccountShareController.php receives a caller-selected TwoFAccount through Laravel model binding but does not call the manageShares authorization policy before listing its recipients. When account sharing is enabled, an authenticated user can call GET /api/v1/twofaccounts/{victimId}/recipients for accounts owned by other users, enumerate registered user IDs and display names, test exact email addresses with filter[nameOrEmail], and inspect each account's sharing relationships. This issue is fixed in version 8.0.0.

Patch / fix

links 2

github.com/Bubka/2FAuth@08753af commit
github.com/Bubka/2FAuth/releases/tag/v8.0.0 release

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

Bubka 2FAuth

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

References

Sources

CVE List CVE-2026-63437
NVD CVE-2026-63437

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary