{"apiVersion":"1.0","identifier":"CVE-2026-45125","description":"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.","publishedAt":"2026-08-18T16:17:07","lastModifiedAt":"2026-08-18T18:17:36","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-45125","cvssScore":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","epssProbability":0.00302,"riskScore":0.54,"affectedProduct":"MyBB","affectedVersions":"<1.8.40","vulnerabilityType":"Web app","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-45125","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-45125","en":"https://www.redsauce.net/en/cves/CVE-2026-45125","fr":"https://www.redsauce.net/fr/cves/CVE-2026-45125","pt":"https://www.redsauce.net/pt/cves/CVE-2026-45125","de":"https://www.redsauce.net/de/cves/CVE-2026-45125","sk":"https://www.redsauce.net/sk/cves/CVE-2026-45125","el":"https://www.redsauce.net/el/cves/CVE-2026-45125"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-45125"}}