Arbitrary file read via URL-fragment suffix bypass
Published Aug 20, 2026 · Updated Aug 25, 2026
Path traversal in Handlebars.java before 4.5.3 allows remote attackers to read JVM-accessible files through crafted Spring MVC view names. SpringTemplateLoader appends .hbs to an attacker-controlled file: or classpath: URL, but a trailing fragment delimiter moves that suffix into a fragment discarded before the resource stream opens. Exploitation requires a controller that passes a fully or partly user-influenced view name to HandlebarsViewResolver, and disclosure is limited to files readable by the JVM process.
Summary
What happened
Path traversal in Handlebars.java before 4.5.3 allows remote attackers to read JVM-accessible files through crafted Spring MVC view names. SpringTemplateLoader appends .hbs to an attacker-controlled file: or classpath: URL, but a trailing fragment delimiter moves that suffix into a fragment discarded before the resource stream opens. Exploitation requires a controller that passes a fully or partly user-influenced view name to HandlebarsViewResolver, and disclosure is limited to files readable by the JVM process.
The record
- CVE
- CVE-2026-63490
- Published
- Aug 20, 2026
- Updated
- Aug 25, 2026
- Vendor
- jknack
- Product
- Handlebars.java
- Classifications
- CWE-23, CWE-22, CWE-552, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 20, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.5.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- URL-fragment suffix-bypass proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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