CVE-2024-43787 Hono CSRF middleware can be bypassed using crafted Content-Type header
Attackers can bypass CSRF protection in the Hono framework by using uppercase MIME types in Content-Type headers, allowing unauthorized state-changing requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2024-43787?
CVE-2024-43787 is a medium-severity vulnerability in honojs hono, published on 22 Aug 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Hono is a Web application framework that provides support for any JavaScript runtime. Hono CSRF middleware can be bypassed using crafted Content-Type header. MIME types are case insensitive, but isRequestedByFormElementRe only matches lower-case. As a result, attacker can bypass csrf middleware using upper-case form-like MIME type. This vulnerability is fixed in 4.5.8.
Weakness: CWE-352
Which versions are affected by CVE-2024-43787?
2 open source packages ship an affected version, including hono. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
hono npm | All versions | 4.5.8 |
hono npm | All versions | 4.5.8 |
Products include Hono Hono.
How do I fix CVE-2024-43787?
Upgrade hono to 4.5.8 or later.
Is CVE-2024-43787 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-43787 exists.
Other vulnerabilities in honojs hono
- CVE-2026-27700 Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo
- CVE-2026-22817 JWT Algorithm Confusion via Unsafe Default (HS256) in Hono JWT Middleware Allows Token Forgery and Auth Bypass
- CVE-2026-22818 JWT algorithm confusion in Hono JWK Auth Middleware when JWK lacks "alg" (untrusted header.alg fallback)
- CVE-2025-62610 Hono Improperly Authorizes JWT Audience Validation
- CVE-2026-29045 Hono: Arbitrary file access via serveStatic vulnerability
Sources
Also known as GHSA-rpfr-3m35-5vx5.