{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45125","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-08T20:08:17.208Z","datePublished":"2026-08-18T15:50:38.936Z","dateUpdated":"2026-08-18T17:46:25.763Z"},"containers":{"cna":{"title":"MyBB: Email User CRLF injection","problemTypes":[{"descriptions":[{"cweId":"CWE-93","lang":"en","description":"CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/mybb/mybb/security/advisories/GHSA-f626-53q9-pqm9","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mybb/mybb/security/advisories/GHSA-f626-53q9-pqm9"},{"name":"https://github.com/mybb/mybb/commit/5046c56b515d4593297a4f65b0c6ccb0b55baa01","tags":["x_refsource_MISC"],"url":"https://github.com/mybb/mybb/commit/5046c56b515d4593297a4f65b0c6ccb0b55baa01"},{"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":"2026-08-18T15:50:38.936Z"},"descriptions":[{"lang":"en","value":"MyBB is free and open source forum software. Prior to 1.8.40, the Email User controller does not sanitize sender names correctly, resulting in mail header injection. member.php?action=do_emailuser accepts the fromname HTTP parameter for guests or the stored username for authenticated users when the cansendemail group permission is enabled. When mail_handler is set to the default PHP mail value, the sender name is used without sanitization in Return-Path and Reply-To headers, allowing arbitrary headers to be injected with CRLF sequences. This issue is fixed in version 1.8.40."}],"source":{"advisory":"GHSA-f626-53q9-pqm9","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T17:44:38.156362Z","id":"CVE-2026-45125","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"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":"2026-08-18T17:46:25.763Z"}}]}}