What’s Vulnerable › Vulnerabilities
CVE-2026-47675: Hono: Cookie helper does not sanitize sameSite and priority, allowing Set-Cookie injection
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-05-28 · updated 2026-10-14
- Weakness: CWE-113
Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the serialize() function in hono/cookie validates domain and path options against characters that corrupt Set-Cookie header syntax (;, \r, \n), but does not apply the same validation to sameSite and priority. An application that passes user-controlled input into either option may produce a Set-Cookie response header containing attacker-chosen additional attributes. This vulnerability is fixed in 4.12.21.
Affected products
- honojs hono: before 4.12.21 — fixed in 4.12.21
How to fix
Upgrade to a fixed version: honojs hono 4.12.21. Check the vendor advisory for mitigations.
References
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