CVE-2026-111639 json
bbs-go through 4.4.6 Account Takeover via Google One Tap Login
published 24d ago modified 19d ago also EUVD-2026-103061
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 41%
- public exploits
- 0
- none known
Summary
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.
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 19d ago
Exploit prediction
0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- hackmd.io https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.6 | 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 |
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N |
| CNA | 4.0 | 8.6 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- mlogclub bbs-go
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
hackmd.io
/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover
third-party-advisory, exploit
-
github.com
/mlogclub/bbs-go/blob/v4.4.6/internal/pkg/google/jwt.go#L55-L58
technical-description
-
github.com
/mlogclub/bbs-go/blob/v4.4.6/internal/services/third_user_service.go#L274-L293
technical-description
-
vulncheck.com
/advisories/bbs-go-through-4.4.6-account-takeover-via-google-one-tap-login
third-party-advisory
Sources
- CVE List CVE-2026-111639
- NVD CVE-2026-111639
Fencer Intel 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.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.