A AegiFlow
MEDIUMCVSS 6.9

GHSA-55cm-p4ww-685g

Duplicate Advisory: Hono missing validation of cookie name on write path in setCookie()

Published
2026-06-23
Modified
2026-09-24
Sources
github-advisory

Summary

### Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-26pp-8wgv-hjvm. This link is maintained to preserve external references. ### Original Description 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.

Affected packages

EcosystemPackageAffected versionsFixed versions
npmhono—4.12.12

Remediation: Upgrade to 4.12.12 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.