Path Traversal in Contao
CVE-2026-107844
Contao is an Open Source CMS. From version 5.0.0 until 5.3.50 and 5.7.12, ImagesController joins the user-controlled {path} parameter to the configured image target directory with Path::join() but does not use Path::isBasePath() to verify that the canonical path remains inside that directory. An unauthenticated request containing encoded parent-directory segments can therefore return files under the project directory through BinaryFileResponse when their names use an extension allowed by contao.image.valid_extensions. The route can also reveal whether arbitrary paths exist, and debug responses can disclose absolute filesystem paths, but paths below the upload directory were not shown to be readable. This issue is fixed in versions 5.3.50 and 5.7.12.
Vulnerability class: Path Traversal (Directory Traversal)
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Contao — versions >= 5.0.0, < 5.3.50, >= 5.4.0-RC1, < 5.7.12
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-107844?
- CVE-2026-107844 is a medium-severity vulnerability in Contao, classified under Path Traversal. CVSS score: 5.3/10. Published 2026-10-09.
- How severe is CVE-2026-107844?
- Medium severity. CVSS v3 base score is 5.3 out of 10.