jknack handlebars.java up to 4.5.4 URL handler path traversal

Summaryinfo

A vulnerability described as problematic has been identified in jknack handlebars.java up to 4.5.4. Affected is an unknown function of the component URL handler. Executing a manipulation can lead to path traversal. This vulnerability is registered as CVE-2026-103088. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in jknack handlebars.java up to 4.5.4. This vulnerability affects an unknown code block of the component URL handler. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality. CVE summarizes:

Handlebars.java before 4.5.5 allows directory traversal. In handlebars-springmvc 4.5.3 and 4.5.4, the path-containment fix for CVE-2026-63490 validates template locations as raw percent-encoded strings, whereas the template file is opened through a URL handler that percent-decodes the path. In a Spring MVC application with a file: template prefix and a request-derived view name, a percent-encoded traversal such as %2e%2e/ bypasses both the view-resolver check and the loader-side containment and reads files outside the configured template base directory.

The advisory is available at github.com. This vulnerability was named CVE-2026-103088 since 09/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

Upgrading to version 4.5.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-89555). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Programming Language Software

Vendor

• jknack

Name

• handlebars.java

Version

• 4.5.0
• 4.5.1
• 4.5.2
• 4.5.3
• 4.5.4

Website

• Product: https://github.com/jknack/handlebars.java/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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