{"id":"CVE-2026-39912","title":"v2board / Xboard Authentication Token Exposure via loginWithMailLink","summary":"V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unauthenticated attackers can POST to the…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cvssSource":"cna","cwe":["CWE-201"],"vendor":"v2board","product":"v2board","affected":["v2board >= 1.6.1 <= 1.7.4","v2board >= bdb10bed32c5f37df2f0872c3cb354e9b7a293bd <= 0ca47622a50116d0ddd7ffb316b157afb57d25e8","Xboard <= 0.1.9"],"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"total","timestamp":"2026-04-10T20:16:59.517212Z"},"exploitAvailable":true,"published":"2026-04-09","updated":"2026-11-08","sourceUpdated":"2026-11-08T14:02:33.091Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-39912","references":[{"url":"https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/"},{"url":"https://github.com/v2board/v2board/pull/981"},{"url":"https://github.com/cedar2025/Xboard/pull/873"},{"url":"https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71"},{"url":"https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49"},{"url":"https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51"},{"url":"https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957"},{"url":"https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink"}],"tags":["cve.org","exploit-available"],"epss":0.00607,"epssPercentile":0.4929,"exploits":{"github":1,"githubRepos":["https://github.com/Chocapikk/CVE-2026-39912"],"checkedAt":"2026-11-08T14:51:57.347Z"},"ingestedAt":"2026-11-08T14:51:22.447Z","slug":"CVE-2026-39912","body":"## Overview\n\nV2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unauthenticated attackers can POST to the loginWithMailLink endpoint with a known email address to receive the full authentication URL in the response, then exchange the token at the token2Login endpoint to obtain a valid bearer token with complete account access including admin privileges.\n\n## Affected\n\n- `v2board >= 1.6.1 <= 1.7.4`\n- `v2board >= bdb10bed32c5f37df2f0872c3cb354e9b7a293bd <= 0ca47622a50116d0ddd7ffb316b157afb57d25e8`\n- `Xboard <= 0.1.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"abyssal","depthScore":62,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}