PatchSiren cyber security CVE debrief
CVE-2026-55760 jknack CVE debrief
CVE-2026-55760 is a high-severity vulnerability in Handlebars.java, a Java library for logic-less and semantic Mustache templates. Prior to version 4.5.2, applications using FileTemplateLoader or ClassPathTemplateLoader and passing user-controlled input to Handlebars.compile() are vulnerable to path traversal attacks. This could allow attackers to read arbitrary files through template names derived from URL path parameters, request parameters, or other user-controlled sources. The issue is fixed in version 4.5.2.
- Vendor
- jknack
- Product
- handlebars.java
- CVSS
- HIGH 7.5
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-08
- Original CVE updated
- 2026-07-10
- Advisory published
- 2026-07-08
- Advisory updated
- 2026-07-10
Who should care
Developers and administrators using Handlebars.java in their applications should be aware of this vulnerability and take steps to mitigate it, especially if user-controlled input is passed to the Handlebars.compile() method.
Technical summary
The vulnerability exists in Handlebars.java versions prior to 4.5.2. It is caused by the library's handling of user-controlled input to the Handlebars.compile() method when using FileTemplateLoader or ClassPathTemplateLoader. This allows attackers to perform path traversal attacks, potentially leading to arbitrary file reads. The CVSS score for this vulnerability is 7.5, classified as HIGH severity.
Defensive priority
High priority should be given to updating Handlebars.java to version 4.5.2 or later, especially in applications that use FileTemplateLoader or ClassPathTemplateLoader with user-controlled input.
Recommended defensive actions
- Update Handlebars.java to version 4.5.2 or later
- Review applications using FileTemplateLoader or ClassPathTemplateLoader with user-controlled input
- Implement input validation and sanitization for template names
- Monitor for suspicious file access patterns
- Perform a thorough review of the application's codebase to identify potential vulnerabilities
- Inventory assets that may be affected by this vulnerability and prioritize their remediation
- Track exceptions and retest remediated assets to ensure the vulnerability is fully resolved
Evidence notes
The CVE record was published on 2026-07-08T20:16:53.287Z and last modified on 2026-07-10T19:13:03.283Z. The NVD entry is currently awaiting analysis. Developers should verify the affected versions and configurations of Handlebars.java in their applications, focusing on instances where user-controlled input is passed to Handlebars.compile() using FileTemplateLoader or ClassPathTemplateLoader. Evidence is limited, and defenders should monitor for suspicious file access patterns and review template names derived from URL path parameters, request parameters, or other user-controlled sources.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-08T20:16:53.287Z and has not been modified since then. The NVD entry is currently Awaiting Analysis.