CVE-2026-111639
bbs-go through 4.4.6 Account Takeover via Google One Tap Login
- State
- Published
- Severity
- 8.6 High
- Published
- Oct 16, 2026
- Updated
- Oct 21, 2026
- Reserved
- Oct 16, 2026
Description
bbs-go through 4.4.6 contains an authentication bypass vulnerability in the /api/login/google_one_tap endpoint that allows remote attackers to log in as other users by submitting Google ID tokens issued to any OAuth client. Attackers operating their own Google OAuth client can capture a victim's Google-signed ID token and replay it, since the aud claim is never checked, to obtain an authenticated session as the victim's Google-linked account.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.6 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
bbs-gomlogclub |
|
References
- https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeoverthird-party-advisory
- https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/pkg/google/jwt.go#L55-L58technical-description
- https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/services/third_user_service.go#L274-L293technical-description
- VulnCheck Advisory: bbs-go through 4.4.6 Account Takeover via Google One Tap Loginthird-party-advisory
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