HTTP Response Splitting Affecting hono package, versions <4.12.21
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-17055753
- published29 May 2026
- disclosed28 May 2026
- creditoffset
Introduced: 28 May 2026
NewCVE-2026-47675 (opens in a new tab)How to fix?
Upgrade hono to version 4.12.21 or higher.
Overview
hono is an Ultrafast web framework for the Edges
Affected versions of this package are vulnerable to HTTP Response Splitting via the serialize function. An attacker can inject arbitrary attributes into the Set-Cookie response header by supplying crafted input to the sameSite or priority options.