medium4.3
CVE-2026-47675
Hono: Cookie helper does not sanitize sameSite and priority, allowing Set-Cookie injection
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | hono | < 4.12.21 | 4.12.21 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Hono | Hono | before 4.12.21 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3hrh-pfw6-9m5x
- https://github.com/honojs/hono/security/advisories/GHSA-3hrh-pfw6-9m5x
- https://nvd.nist.gov/vuln/detail/CVE-2026-47675
- https://github.com/honojs/hono/commit/905aedbc20661e0e2fa378783a7ec44a5c3df43d
- https://github.com/honojs/hono/releases/tag/v4.12.21