Read the docs
TI-2026-40926 Aliases CVE-2026-56762GHSA-26pp-8wgv-hjvm

Hono - Missing Cookie Name Validation in setCookie()

Priority LOW 37CWE-20Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

Hono before 4.12.12 does not validate cookie names on the write path in the setCookie(), serialize(), and serializeSigned() functions, allowing invalid characters such as control characters (e.g. \r or \n) when an application passes a user-controlled cookie name. This can produce malformed Set-Cookie header values. In modern runtimes such as Node.js and Cloudflare Workers, such invalid header values are rejected and cause a runtime error before the response is sent, so header injection or response splitting could not be reproduced; the issue primarily affects correctness and robustness, resulting in runtime errors (availability) rather than confirmed header injection.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00418 36th percentileScored 2026-11-07
Fix Fixed Hono (Hono): 4.12.12hono (npm): 4.12.12

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 4.12.124.12.12Patch availableCNA
—hono (npm)before 4.12.124.12.12Patch availableGHSA-26pp-8wgv-hjvm
  • Hono Vendorhonojs Affected before 4.12.12 Fixed in 4.12.12 Patch available CNA
  • hono (npm) Vendor— Affected before 4.12.12 Fixed in 4.12.12 Patch available GHSA-26pp-8wgv-hjvm

Remediation

  • Fix · CNA Hono (Hono) Fixed in 4.12.12
  • Fix · GHSA-26pp-8wgv-hjvm hono (npm) Fixed in 4.12.12 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56762
  2. 2026-10-03 Alias added: GHSA-26pp-8wgv-hjvm

References

Advisory 2

Other 3

  • TI-2024-21741 Hono vulnerable to Restricted Directory Traversal in serveStatic with deno CVSS 3.1MEDIUM 5.3
  • TI-2024-15441 @hono/node-server can't handle "double dots" in URL 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-2026-39189 Hono: Lambda@Edge adapter keeps only the last value of a repeated request header, dropping the rest CVSS 3.1MEDIUM 4.8
  • TI-2026-23190 Hono: Arbitrary file access via serveStatic vulnerability CVSS 3.1CRITICAL 9.8
See all 59 →

Sources

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