CVE-2026-39410
Medium
Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a discrepancy between browser cookie parsing and parse() handling allows cookie prefix protections to be bypassed. Cookie names that are treated as distinct by the browser may be normalized to the same key by parse(), allowing attacker-controlled cookies to override legitimate ones. This vulnerability is fixed in 4.12.12.
SeverityMedium
CVSS4.8
Exploit probability—
Product
Hono
PublishedApr 8, 2026
First seenApr 8, 2026
Weakness typeCWE-20Improper input validation
How to fix
Update
- hono4.12.12 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| hono hono | v ≤ 4.12.11 | — |
| hononpm | v < 4.12.12 | 4.12.12 |
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