CVE-2026-29045: Hono vulnerable to arbitrary file access via serveStatic vulnerability

March 4, 2026 (updated March 5, 2026)

When using serveStatic together with route-based middleware protections (e.g. app.use('/admin/*', ...)), inconsistent URL decoding allowed protected static resources to be accessed without authorization.

The router used decodeURI, while serveStatic used decodeURIComponent. This mismatch allowed paths containing encoded slashes (%2F) to bypass middleware protections while still resolving to the intended filesystem path.

References

github.com/advisories/GHSA-q5qw-h33p-qvwr
github.com/honojs/hono
github.com/honojs/hono/commit/6a0607a929d888893f0c91d92dce2fcfdb3662a3
github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr
nvd.nist.gov/vuln/detail/CVE-2026-29045

Code Behaviors & Features

Detect and mitigate CVE-2026-29045 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →