What’s Vulnerable › Vulnerabilities

CVE-2026-63490: Handlebars.java: Arbitrary file read in `SpringTemplateLoader` via URL-fragment suffix bypass

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-20 · updated 2026-10-18
• Weakness: CWE-22

Description

Handlebars.java provides logic-less and semantic Mustache templates with Java. Prior to 4.5.3, com.github.jknack.handlebars.springmvc.SpringTemplateLoader resolves attacker-influenced Spring MVC view names through Spring ResourceLoader without the path-containment validation used by other URL-based loaders. In handlebars-springmvc/src/main/java/com/github/jknack/handlebars/springmvc/SpringTemplateLoader.java, a view name using a file: or classpath: URL and ending with the # fragment delimiter places the appended .hbs suffix in the fragment, which FileUrlResource.exists() and URL.openStream() discard. HandlebarsViewResolver in handlebars-springmvc/src/main/java/com/github/jknack/handlebars/springmvc/HandlebarsViewResolver.java then passes the attacker-controlled name to handlebars.compile(), allowing an unauthenticated remote attacker to read files accessible to the JVM when an application exposes a controller with a user-influenced view name. This issue is fixed in version 4.5.3.

Affected products

• jknack handlebars.java: before 4.5.3

References

• https://github.com/jknack/handlebars.java/commit/61f43423a337b87db5fec1fe59f0725aaaa38df5
• https://github.com/jknack/handlebars.java/releases/tag/v4.5.3
• https://github.com/jknack/handlebars.java/security/advisories/GHSA-g29j-rwfv-h99w
• https://github.com/jknack/handlebars.java/security/advisories/GHSA-g29j-rwfv-h99w

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