{"id":"CVE-2026-111639","title":"bbs-go through 4.4.6 Account Takeover via Google One Tap Login","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 ope…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","cvssSource":"cna","cwe":["CWE-287"],"vendor":"mlogclub","product":"bbs-go","affected":["bbs-go <= 4.4.6"],"published":"2026-10-16","updated":"2026-10-16","sourceUpdated":"2026-10-16T17:39:10.284Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-111639","references":[{"url":"https://hackmd.io/@hieuPenguinnn/bbs-go-google-one-tap-id-token-audience-confusion-account-takeover"},{"url":"https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/pkg/google/jwt.go#L55-L58"},{"url":"https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/services/third_user_service.go#L274-L293"},{"url":"https://www.vulncheck.com/advisories/bbs-go-through-4.4.6-account-takeover-via-google-one-tap-login","label":"VulnCheck Advisory: bbs-go through 4.4.6 Account Takeover via Google One Tap Login"}],"tags":["cve.org"],"ingestedAt":"2026-10-16T18:43:08.682Z","slug":"CVE-2026-111639","body":"## Overview\n\nbbs-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.\n\n## Affected\n\n- `bbs-go <= 4.4.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}