{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45123","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-08T20:08:17.208Z","datePublished":"2026-08-18T15:44:26.555Z","dateUpdated":"2026-08-18T18:55:56.614Z"},"containers":{"cna":{"title":"MyBB: IPv6 SSRF","problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/mybb/mybb/security/advisories/GHSA-56wr-64wx-5g7j","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mybb/mybb/security/advisories/GHSA-56wr-64wx-5g7j"},{"name":"https://github.com/mybb/mybb/commit/9cdadbf66f4cef50019f13aaa8e3470ea6535cb7","tags":["x_refsource_MISC"],"url":"https://github.com/mybb/mybb/commit/9cdadbf66f4cef50019f13aaa8e3470ea6535cb7"},{"name":"https://github.com/mybb/mybb/releases/tag/mybb_1840","tags":["x_refsource_MISC"],"url":"https://github.com/mybb/mybb/releases/tag/mybb_1840"},{"name":"https://mybb.com/versions/1.8.40","tags":["x_refsource_MISC"],"url":"https://mybb.com/versions/1.8.40"}],"affected":[{"vendor":"mybb","product":"mybb","versions":[{"version":"< 1.8.40","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-18T15:44:26.555Z"},"descriptions":[{"lang":"en","value":"MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetch_remote_file() fails open when get_ip_by_hostname() returns no result because that function does not return IPv6 results, allowing a crafted remote target to bypass the host restriction. The uniquely identifying implementation details include fail-open verification, and inc/functions.php. This issue is fixed in version 1.8.40."}],"source":{"advisory":"GHSA-56wr-64wx-5g7j","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T18:55:46.017873Z","id":"CVE-2026-45123","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-18T18:55:56.614Z"}}]}}