VulnerabilityPublished 12 Nov 2026

CVE-2026-126344: honojs node-server · Missing Origin Validation in WebSockets

Affects honojs node-serverSource CVE Database V5

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 2.1.6 when convenient.

Data as of 12 Nov 2026, 21:35 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.4

Patch: Available – fixed in 2.1.6

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade honojs node-server to 2.1.6.

Affected software

Product	Affected	Fixed in
honojsnode-server	Affected >=2.0.0 <2.1.6	Fixed in 2.1.6

AI-suggested

Upgrade honojs node-server to version 2.1.6 or later, where this vulnerability is fixed. No other mitigation is required as the fix addresses the origin validation bypass in the WebSocket upgrade path.

Description

A missing origin validation vulnerability exists in honojs node-server versions 2.0.0 through 2.1.5. The WebSocket upgrade path incorrectly resolves request targets starting with //, causing the URL parser to replace the host in the request URL. This allows an attacker to bypass origin checks, potentially enabling cross-origin WebSocket connections that can access victim cookies and send or receive messages. The issue is fixed in version 2.1.6.

Impact

An attacker can bypass origin validation in WebSocket connections, enabling cross-origin WebSocket access to victim cookies and message exchange. This can lead to unauthorized data access or manipulation in applications that rely on the vulnerable versions of honojs node-server and trust the host in c.req.url during WebSocket upgrades. The CVSS 3.1 score is 5.4 (medium severity), indicating limited confidentiality and integrity impact without availability impact.

Summary

The honojs node-server package (versions >=2.0.0 <2.1.6) has a vulnerability in its WebSocket upgrade handling. When a raw request-target begins with //, the WHATWG URL parser treats it as a network-path reference and replaces the host in c.req.url based on the Host header. However, routing continues to use the local WebSocket path, causing origin checks that compare the Origin header with c.req.url to incorrectly validate an attacker's origin as legitimate. This flaw allows a malicious page on another site to open a WebSocket connection with the victim's cookies and interact with the WebSocket if the application uses upgradeWebSocket and trusts the host in c.req.url. Ordinary HTTP requests are unaffected. The vulnerability is tracked as CVE-2026-126344 and is fixed in version 2.1.6.

CWE-1385Missing Origin Validation in WebSockets (opens in a new tab)
Variant weakness
The product uses a WebSocket, but it does not properly verify that the source of data or communication is valid.
Implementation
Enable CORS-like access restrictions by verifying the 'Origin' header during the WebSocket handshake.
Implementation
Use a randomized CSRF token to verify requests.
Implementation
Use TLS to securely communicate using 'wss' (WebSocket Secure) instead of 'ws'.
OWASP ASVS 4.0.3
V14.5.2 (opens in a new tab)
V14.5.3 (opens in a new tab)
V1.4.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Nov 2026, 21:35 UTC

WeaknessesCWE-1385

Technical details

References

Community reviews

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