CVE-2026-58044

A flaw was found in Node.js. The Node.js HTTP client can cause a request desynchronization in forwarding proxies, potentially leading to request smuggling. This vulnerability arises when the HTTP client omits certain headers, such as Content-Length, from being visible to the proxy application while still using them internally for message processing. This inconsistency can allow an attacker to bypass security controls and inject malicious requests, impacting the integrity of network communications.

This flaw impacts Confidentiality and Integrity with zero effect on Availability (C:L, I:L, A:N). Practical exploitation occurs when Node.js operates as a forwarding proxy that reconstructs outbound headers from incoming requests while piping the message body over reused backend connections. Header desynchronization between internal processing and application-visible headers allows HTTP request smuggling. Standard Node.js web applications, non-proxy architectures, or proxies that do not reuse backend socket connections are completely unaffected. Red Hat assesses Confidentiality at Low (C:L) rather than None (C:N) because request smuggling in a proxy environment can expose sensitive adjacent request data, resulting in a 4.8 score versus CVEOrg's 3.7.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.