CVE-2026-58040

A flaw was found in Node.js. An incomplete fix for a previous vulnerability allows the HTTPS Agent to reuse Transport Layer Security (TLS) sessions, bypassing hostname verification across different identity policies. This could enable an attacker to impersonate a legitimate server, leading to information disclosure or other security breaches.

This issue is rated Moderate (CVSS 6.3) because successful exploitation allows session-hijacking and information disclosure without affecting system integrity or availability (C:H, I:N, A:N). The flaw occurs when an HTTPS Agent reuses an existing TLS session across requests with differing identity policies, skipping host verification. An attacker must already sit in a privileged network position (AV:N/AC:H) to perform a man-in-the-middle attack and intercept traffic intended for a distinct target on the same TLS session.

Applications that explicitly configure unique HTTPS agents per target host, avoid TLS session caching, or do not make outbound HTTPS requests to varied third-party endpoints using shared client instances are not at risk.

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.

To mitigate this issue, Node.js applications should be designed to explicitly configure unique HTTPS agents for each distinct target host. Alternatively, applications can avoid TLS session caching when making outbound HTTPS requests to varied third-party endpoints using shared client instances. Implementing these application-level changes will prevent the vulnerable behavior of skipping hostname verification. Applications may require a restart to apply these changes.