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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-126344: @hono/node-server: WebSocket upgrade request-target starting with `//` replaces the host in `c.req.url`, bypassing `Origin` checks

MediumCVSS 5.4 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: honojs node-server 2.1.6.

Low priority for now. Upgrade to honojs node-server 2.1.6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org

@hono/node-server allows running the Hono application on Node.js. From 2.0.0 until 2.1.6, the WebSocket upgrade path resolves a raw request-target beginning with // against a base URL built from the Host header, causing the WHATWG URL parser to treat the request-target as a network-path reference and replace the host in c.req.url. Routing still uses the local WebSocket path, so an application that compares the Origin header with the origin of c.req.url, including checks implemented with csrf(), compares an attacker's origin with itself and accepts the connection. A page on another site can consequently open a WebSocket with the victim's cookies and read and send messages when the application uses upgradeWebSocket and trusts the host in c.req.url. Ordinary HTTP requests are not affected. This issue is fixed in version 2.1.6.

Published
Nov 12, 2026
Updated
Nov 13, 2026
EPSS
—

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · —

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.4
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • honojs node-server

    • >= 2.0.0, < 2.1.6affected

Same product

honojs: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-126343@hono/node-server: Unhandled `ECONNRESET` on the socket during an asynchronous WebSocket upgrade crashes the process
    21Monitor
  • CVE-2026-126210@hono/node-server: Backslash in the request path is parsed as a path separator, bypassing path-based access control at a reverse proxy
    21Monitor
  • CVE-2026-118663@hono/node-server: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths
    21Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-73565Aug 13, 2026 · @hono/node-server: Unauthenticated memory-leak DoS via aborted WebSocket handshake
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
honojs node-server2.1.6 · descriptionVendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+1 d

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-1385 · Missing Origin Validation in WebSockets

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → none
  3. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records