{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-39912","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-04-07T20:57:06.209Z","datePublished":"2026-04-09T18:35:35.569Z","dateUpdated":"2026-06-23T16:16:26.058Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-06-23T16:16:26.058Z"},"title":"v2board / Xboard Authentication Token Exposure via loginWithMailLink","descriptions":[{"lang":"en","value":"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 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.","supportingMedia":[{"type":"text/html","base64":false,"value":"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 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.<br>"}]}],"affected":[{"vendor":"v2board","product":"v2board","repo":"https://github.com/v2board/v2board","versions":[{"status":"affected","version":"1.6.1","lessThanOrEqual":"1.7.4","versionType":"semver"},{"status":"affected","version":"bdb10bed32c5f37df2f0872c3cb354e9b7a293bd","lessThanOrEqual":"0ca47622a50116d0ddd7ffb316b157afb57d25e8","versionType":"git"}],"defaultStatus":"unknown"},{"vendor":"cedar2025","product":"Xboard","repo":"https://github.com/cedar2025/Xboard","versions":[{"status":"affected","version":"0","lessThanOrEqual":"0.1.9","versionType":"semver"},{"status":"unaffected","version":"121511523f04882ec0c7447acd9b8ebcb8a47957","versionType":"git"}],"defaultStatus":"unaffected"}],"problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-201","description":"CWE-201 Insertion of Sensitive Information Into Sent Data","type":"CWE"}]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":9.1,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseSeverity":"CRITICAL","baseScore":9.1,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"}}],"source":{"discovery":"EXTERNAL"},"references":[{"url":"https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/","tags":["technical-description","exploit"]},{"url":"https://github.com/v2board/v2board/pull/981","tags":["issue-tracking"]},{"url":"https://github.com/cedar2025/Xboard/pull/873","tags":["issue-tracking"]},{"url":"https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71","tags":["related"]},{"url":"https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49","tags":["related"]},{"url":"https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51","tags":["related"]},{"url":"https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957","tags":["patch"]},{"url":"https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink","tags":["third-party-advisory"]}],"credits":[{"lang":"en","value":"Valentin Lobstein (Chocapikk)","type":"finder"}],"x_generator":{"engine":"vulncheck"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-10T20:16:59.517212Z","id":"CVE-2026-39912","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-13T15:38:46.529Z"}}]}}