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TI-2026-35183 Aliases CVE-2026-47676GHSA-2gcr-mfcq-wcc3

Hono: app.mount() strips mount prefix using undecoded path, causing incorrect routing for percent-encoded paths

Priority LOW 30CWE-444Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-693.

Summary

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed against the percent-decoded path. This inconsistency causes the prefix to be stripped at the wrong position when the path contains percent-encoded multi-byte characters, resulting in the mounted sub-application receiving an incorrect path. This vulnerability is fixed in 4.12.21.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0026 17th percentileScored 2026-11-07
Fix Fixed hono (honojs): 4.12.21hono (npm): 4.12.21

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
honojshonobefore 4.12.214.12.21Patch availableCNA
—hono (npm)before 4.12.214.12.21Patch availableGHSA-2gcr-mfcq-wcc3
  • hono Vendorhonojs Affected before 4.12.21 Fixed in 4.12.21 Patch available CNA
  • hono (npm) Vendor— Affected before 4.12.21 Fixed in 4.12.21 Patch available GHSA-2gcr-mfcq-wcc3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*before 4.12.21Vulnerablehonojs
  • cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:* Versions before 4.12.21 Vulnerable ·honojs

Remediation

  • Fix · CNA hono (honojs) Fixed in 4.12.21
  • Fix · GHSA-2gcr-mfcq-wcc3 hono (npm) Fixed in 4.12.21 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-47676
  2. 2026-10-03 Alias added: GHSA-2gcr-mfcq-wcc3

References

Advisory 2

Other 3

  • TI-2024-21741 Hono vulnerable to Restricted Directory Traversal in serveStatic with deno CVSS 3.1MEDIUM 5.3
  • TI-2024-32610 Hono vulnerable to bypass of CSRF Middleware by a request without Content-Type header. CVSS 3.1MEDIUM 5.9
  • TI-2024-29381 Hono CSRF middleware can be bypassed using crafted Content-Type header CVSS 3.1MEDIUM 5.0
  • TI-2026-23190 Hono: Arbitrary file access via serveStatic vulnerability CVSS 3.1CRITICAL 9.8
  • TI-2026-22076 Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo CVSS 3.1HIGH 8.2
  • TI-2026-18334 JWT algorithm confusion in Hono JWK Auth Middleware when JWK lacks "alg" (untrusted header.alg fallback) CVSS 3.1HIGH 8.2
See all 33 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences