Improper Encoding or Escaping of Output Affecting hono package, versions <4.12.25
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-HONO-17356429
- published17 Jun 2026
- disclosed16 Jun 2026
- creditRootingg
Introduced: 16 Jun 2026
NewCVE-2026-54287 (opens in a new tab)How to fix?
Upgrade hono to version 4.12.25 or higher.
Overview
hono is an Ultrafast web framework for the Edges
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output in the AWS Lambda adapter's handling of multiple Set-Cookie headers. An attacker can cause clients to drop or misinterpret cookies by triggering responses that set multiple cookies, leading to broken sessions, forced re-authentication, or failure of preference and CSRF cookies. This is only exploitable if the application is deployed on AWS Lambda behind an ALB in single-header mode or VPC Lattice v2.