CVE-2026-111639

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.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/pkg/google/jwt.go#L55-L58
https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/services/third_user_service.go#L274-L293
https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover
https://www.vulncheck.com/advisories/bbs-go-through-4.4.6-account-takeover-via-google-one-tap-login
https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover

Configurations

No configuration.

History

21 Oct 2026, 21:17

Type	Values Removed	Values Added
References	~~() https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover -~~	() https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover -

16 Oct 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-16 18:17

Updated : 2026-10-21 21:17

NVD link : CVE-2026-111639

Mitre link : CVE-2026-111639

CVE.ORG link : CVE-2026-111639

JSON object : View

Products Affected

No product.

CWE

CWE-287

Improper Authentication

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