{"id":"CVE-2026-45118","state":"PUBLISHED","title":"MyBB: Contact page reflected XSS","description":"MyBB is free and open source forum software. Prior to 1.8.40, the Contact module does not validate a redirect URL or protocol correctly, resulting in an open redirect and reflected JavaScript code injection. contact.php accepts the redirect target from the from HTTP parameter in $mybb->input['from'] or the Referer HTTP header in $_SERVER['HTTP_REFERER'] and passes it to redirect() without sufficient verification. A javascript: URI becomes the target of the `Click here if you don't want to wait any longer` link because $force_redirect is true, allowing script execution when a victim selects the link. This issue is fixed in version 1.8.40.","publishedAt":"2026-08-18T15:55:27.280Z","updatedAt":"2026-08-18T17:52:25.117Z","severity":{"score":9.3,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["mybb mybb"],"affected":[{"vendor":"mybb","product":"mybb","versions":[{"version":"< 1.8.40","status":"affected"}]}],"references":["https://github.com/mybb/mybb/security/advisories/GHSA-wf92-5q5h-qr53","https://github.com/mybb/mybb/releases/tag/mybb_1840","https://mybb.com/versions/1.8.40"],"weaknesses":["CWE-83"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45118.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45118","state":"PUBLISHED","datePublished":"2026-08-18T15:55:27.280Z","dateUpdated":"2026-08-18T17:52:25.117Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-08T20:08:17.207Z"},"containers":{"cna":{"title":"MyBB: Contact page reflected XSS","descriptions":[{"lang":"en","value":"MyBB is free and open source forum software. Prior to 1.8.40, the Contact module does not validate a redirect URL or protocol correctly, resulting in an open redirect and reflected JavaScript code injection. contact.php accepts the redirect target from the from HTTP parameter in $mybb->input['from'] or the Referer HTTP header in $_SERVER['HTTP_REFERER'] and passes it to redirect() without sufficient verification. A javascript: URI becomes the target of the `Click here if you don't want to wait any longer` link because $force_redirect is true, allowing script execution when a victim selects the link. This issue is fixed in version 1.8.40."}],"affected":[{"vendor":"mybb","product":"mybb","versions":[{"version":"< 1.8.40","status":"affected"}]}],"references":[{"url":"https://github.com/mybb/mybb/security/advisories/GHSA-wf92-5q5h-qr53","name":"https://github.com/mybb/mybb/security/advisories/GHSA-wf92-5q5h-qr53","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/mybb/mybb/releases/tag/mybb_1840","name":"https://github.com/mybb/mybb/releases/tag/mybb_1840","tags":["x_refsource_MISC"]},{"url":"https://mybb.com/versions/1.8.40","name":"https://mybb.com/versions/1.8.40","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-83","lang":"en","description":"CWE-83: Improper Neutralization of Script in Attributes in a Web Page","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-18T15:55:27.280Z"},"source":{"advisory":"GHSA-wf92-5q5h-qr53","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T17:47:24.986811Z","id":"CVE-2026-45118","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-18T17:52:25.117Z"}}]}}}