Vulnerability details

Horde IMP before 7.0.1 contains a path traversal vulnerability in lib/Compose.php that allows authenticated attackers to read arbitrary files from the server filesystem by embedding traversal sequences after a CKEditor path prefix in img src URLs. Attackers can bypass the stripos() prefix validation by appending sequences such as traversal segments after the matching prefix, causing file_get_contents() to read sensitive files whose contents are then exfiltrated as MIME parts in outgoing email; unauthenticated exploitation is also achievable via CSRF against an active authenticated session.

• https://github.com/horde/imp/releases/tag/v7.0.1 release-notes
• https://github.com/horde/imp/pull/85 issue-trackingpatch
• https://github.com/horde/imp/commit/fba972fab72ee6871e5d56e6390bee38593085de patch
• https://www.horde.org/apps/imp product
• https://www.vulncheck.com/advisories/horde-imp-path-traversal-via-compose-php-img-src third-party-advisory
• https://blog.evan.lat/posts/CVE-2026-58451/ technical-descriptionexploit
• http://seclists.org/fulldisclosure/2026/Jul/8