Path Traversal in Horde Imp
CVE-2026-58451
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Horde Imp — versions 0
Weakness classification (CWE)
References
- github.com/horde/imp/releases/tag/v7.0.1 (release-notes)
- github.com/horde/imp/pull/85 (issue-tracking)
- github.com/horde/imp/commit/fba972fab72ee6871e5d56e6390bee38593085de (patch)
- www.horde.org/apps/imp (product)
- www.vulncheck.com/advisories/horde-imp-path-traversal-via-compose-php-img-src (third-party-advisory)
- blog.evan.lat/posts/CVE-2026-58451/ (technical-description, exploit)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-58451?
- CVE-2026-58451 is a medium-severity vulnerability in Horde Imp, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-07-01.
- How severe is CVE-2026-58451?
- Medium severity. CVSS v3 base score is 6.5 out of 10.