Is CVE-2026-126344 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-126344 being exploited in the wild.

How severe is CVE-2026-126344?

Medium severity, with a CVSS score of 5.4, published 12 November 2026.

Which products and versions are affected?

Hono @Hono/Node-Server 2.0.0 to 2.1.5.

Is there a fix for CVE-2026-126344?

Yes: fixed in 2.1.6. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-126344 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-126344?

Check whether you run Hono @Hono/Node-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-126344: @hono/node-server WebSocket upgrade host spoofing bypass

CVE-2026-126344 · Severity: medium · CVSS 5.4 · Published 2026-11-12

@hono/node-server is a Node.js adapter for running Hono web applications. Versions 2.0.0 through 2.1.5 allow attackers on other websites to open WebSocket connections to a vulnerable application using the victim's cookies by exploiting how the library parses WebSocket upgrade requests. Applications that validate the WebSocket Origin header are bypassed, enabling an attacker to read and send messages on the victim's behalf.

Technologies: Hono @Hono/Node-Server. Vendors: Hono.

Quick answers

Is CVE-2026-126344 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-126344 being exploited in the wild.
How severe is CVE-2026-126344?: Medium severity, with a CVSS score of 5.4, published 12 November 2026.
Which products and versions are affected?: Hono @Hono/Node-Server 2.0.0 to 2.1.5.
Is there a fix for CVE-2026-126344?: Yes: fixed in 2.1.6. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-126344 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-126344?: Check whether you run Hono @Hono/Node-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 2.1.6

Technical details

The WebSocket upgrade path resolves a request-target beginning with // against a Host header-derived base URL using the WHATWG URL parser, which treats such paths as network-path references and replaces the host in c.req.url. Routing continues to use the local WebSocket path, so Origin validation checks comparing the client's Origin with the origin of c.req.url will accept connections from attacker-controlled sites. The vulnerability affects only upgradeWebSocket; ordinary HTTP requests are unaffected.

Affected products

Hono @hono/node-server 2.0.0 to 2.1.5

Timeline

2026-11-12: disclosed
2026-11-02: patched

References

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