Overview
CVE-2026-48615 is a vulnerability in Node.js that affects its proxy tunnel error handling. When proxy credentials are embedded in the proxy URL, they may be exposed through error handling paths and captured by logs, diagnostics, or other error consumers. This vulnerability impacts all supported release lines: Node.js 22, Node.js 24, and Node.js 26.
Understanding the Vulnerability / Threat
Root Cause Analysis
The root cause of this vulnerability is a flaw in the error handling of proxy tunnels in Node.js. Specifically, when proxy credentials are included in the proxy URL, they can be exposed in `ERR_PROXY_TUNNEL` error messages. This is a design issue, as the error handling mechanism does not properly sanitize or redact sensitive information from the proxy URL.
This vulnerability can be classified under CWE-359, which involves exposing sensitive information through error messages.
Attack Surface & Vector
The attack surface for this vulnerability is network-adjacent, as an attacker needs to be able to trigger the error condition that exposes the proxy credentials. The vector involves an attacker being able to capture logs, diagnostics, or other error consumers that may contain the exposed credentials.
Exploitation Mechanics — Scenario Walkthrough
Scenario: Exposing Proxy Credentials Through Error Messages
1.
Initial Position: An attacker has network access to the Node.js application and can trigger an error condition in the proxy tunnel.
2.
Triggering the Flaw: The attacker crafts a request that causes a proxy tunnel error, which includes the proxy credentials in the error message. For example, if the proxy URL is `http://user:
[email protected]`, the error message may contain the string `http://user:
[email protected]`.
3.
What Breaks: The security boundary that fails is the sanitization of sensitive information in error messages. The error handling mechanism does not properly redact the proxy credentials, allowing them to be exposed.
4.
Attacker's Prize: The attacker can now capture the proxy credentials from the error message, gaining unauthorized access to the proxy server.
Real-World Impact
The real-world impact of this vulnerability is significant, as it can lead to the exposure of sensitive proxy credentials. This can result in unauthorized access to proxy servers, potentially allowing attackers to intercept and manipulate sensitive data.
Detection & Defense
Immediate Mitigations
To mitigate this vulnerability, users should upgrade to the latest versions of Node.js: 22.22.4, 24.16.1, or 26.3.1, respectively. Additionally, users can configure their Node.js applications to avoid embedding proxy credentials in proxy URLs.
Detection Strategies
Defenders can detect exploitation attempts by monitoring logs and error messages for suspicious activity, such as error messages containing proxy credentials. They can also implement SIEM rules to alert on potential credential exposure.
Long-Term Hardening
To prevent this class of vulnerability, developers should implement secure error handling mechanisms that properly sanitize and redact sensitive information from error messages. They should also avoid embedding sensitive information in URLs and use secure methods for authentication and authorization.
Key Takeaways
* CVE-2026-48615 is a vulnerability in Node.js that exposes proxy credentials through error messages.
* The vulnerability affects Node.js versions 22, 24, and 26.
* Users should upgrade to the latest versions of Node.js to mitigate the vulnerability.
* Developers should implement secure error handling mechanisms to prevent credential exposure.
Sources
* National Vulnerability Database (NVD)
* Node.js Security Releases