CVE-2026-126355 Hono: `csrf()` does not check requests sent by hyperlink auditing (`text/ping`)
Attackers can bypass Hono's CSRF protection using text/ping requests to change state on endpoints; Hono app developers should care.
- 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
- Harmful if only installed
- No
- Needs a specific call
- Yes
- Fix
- Available
What is CVE-2026-126355?
CVE-2026-126355 is a medium-severity cross-site request forgery vulnerability in honojs hono, published on 12 Nov 2026. 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. Prior to 4.13.16, csrf() limits origin validation to the content types normally sent by HTML forms and therefore does not validate text/ping requests generated by Chromium hyperlink auditing. Chrome and Edge can send a cross-origin credentialed POST without a CORS preflight through an <a ping> action, and the middleware then skips both Origin and Sec-Fetch-Site checks. The fixed request body limits exploitation to state-changing endpoints whose effect is selected by the path or query string and does not depend on submitted body data. The user's cookie must accompany the request, which generally requires a same-site origin or a cookie configured with SameSite=None, and Firefox does not send hyperlink-auditing pings by default. This issue is fixed in version 4.13.16.
Weakness: CWE-352
Which versions are affected by CVE-2026-126355?
1 open source package ship an affected version, including hono.
An affected version is only exploitable if your software calls csrf(). Many projects that include it are not exposed.
| Package | Affected | Fixed in |
|---|---|---|
hono npm | All versions | 4.13.16 |
How do I fix CVE-2026-126355?
Upgrade hono to 4.13.16 or later.
Upgrade, and require an anti-forgery token on every request that changes something. More about Cross-site request forgery.
Is CVE-2026-126355 being exploited?
There is no known exploitation of CVE-2026-126355 in the wild and no public exploit code.
Sources
Also known as GHSA-46wx-v44x-9hh2.