CVE-2026-40465: NSP Open Redirect Vulnerability

CVE-2026-40465 Overview

CVE-2026-40465 is an open redirect vulnerability in Nokia Network Services Platform (NSP). The flaw stems from insufficient server-side validation of the URL or redirect parameter. Attackers can craft URLs that appear to originate from a trusted NSP domain but redirect users to attacker-controlled destinations. This weakness maps to CWE-601: URL Redirection to Untrusted Site.

The vulnerability requires user interaction and high attack complexity, but no authentication is needed to exploit it. Successful exploitation supports phishing, credential harvesting, and malware delivery campaigns that leverage the trust users place in the NSP domain.

Critical Impact
Attackers can weaponize NSP-hosted redirect endpoints to send victims to malicious sites, enabling phishing and credential theft against operators and administrators.

Affected Products

Nokia Network Services Platform (NSP)
Refer to the Nokia Security Advisory CVE-2026-40465 for the definitive list of affected versions
Deployments exposing NSP web interfaces to untrusted networks

Discovery Timeline

2026-08-31 - CVE-2026-40465 published to NVD
2026-09-03 - Last updated in NVD database

Technical Details for CVE-2026-40465

Vulnerability Analysis

CVE-2026-40465 is an open redirect flaw in Nokia NSP. The application accepts a URL or redirect parameter from client requests and issues an HTTP redirect without verifying that the destination belongs to an allowed domain. Attackers can supply an arbitrary external URL as the parameter value and cause the NSP server to forward users to that destination.

Open redirects abuse the trust boundary of the hosting application. A victim inspecting the initial link sees a legitimate NSP hostname, which increases the likelihood of clicking through. After the redirect, the victim lands on an attacker-controlled site that can mimic the NSP login page or deliver malicious payloads.

Exploitation requires user interaction, since the target must click the crafted link. The attack complexity is high because the attacker must construct a convincing phishing lure and time the delivery. However, no privileges are needed and the attack executes over the network.

Root Cause

The root cause is missing or insufficient allowlist validation of the redirect target. The server-side handler treats the URL parameter as trusted input and passes it directly to a redirect response header instead of validating it against a set of approved internal paths or hostnames.

Attack Vector

An attacker crafts a URL of the form https://<nsp-host>/<vulnerable-endpoint>?url=https://attacker.example/phish. The attacker distributes this link through email, chat, or social media targeting NSP users. When the victim clicks the link, NSP responds with an HTTP 3xx redirect pointing to the attacker's site. Refer to the Nokia Security Advisory for endpoint-specific details.

Detection Methods for CVE-2026-40465

Indicators of Compromise

HTTP requests to NSP endpoints containing url=, redirect=, next=, or similar parameters with external hostnames as values
Redirect response codes (301, 302, 303, 307, 308) from NSP with Location headers pointing to non-NSP domains
Spikes in outbound clicks from NSP-hosted URLs to newly registered or low-reputation domains
User reports of NSP login pages that behave unexpectedly after clicking an emailed link

Detection Strategies

Parse NSP web server access logs for query strings containing URL-like values in redirect parameters and compare the destination against an allowlist of internal hosts
Inspect proxy and secure web gateway logs for referrers matching the NSP hostname followed by navigation to unrelated external domains
Deploy phishing simulation and URL reputation scoring on inbound email to flag messages containing NSP URLs with suspicious parameter values

Monitoring Recommendations

Enable verbose HTTP request logging on NSP front-end services and forward logs to a centralized analytics platform
Alert on any Location response header from NSP that points to a domain outside the approved allowlist
Correlate authentication failures on NSP shortly after users click external links referencing NSP hostnames

How to Mitigate CVE-2026-40465

Immediate Actions Required

Review the Nokia Security Advisory CVE-2026-40465 and apply the vendor-supplied fix for your NSP release
Restrict access to NSP management interfaces to trusted management networks and VPNs
Educate NSP users and administrators about phishing links that leverage legitimate NSP hostnames

Patch Information

Nokia has published a product security advisory for CVE-2026-40465. Consult the Nokia Security Advisory for the fixed versions, upgrade paths, and any interim hotfixes applicable to your deployment.

Workarounds

Place a reverse proxy or web application firewall in front of NSP and block requests where redirect parameters contain external URLs or protocol-relative references
Enforce strict Content Security Policy and referrer policies to reduce the effectiveness of downstream phishing attempts
Where redirect parameters are not required for operations, block or strip them at the proxy layer

bash

# Example ModSecurity rule to block open redirect attempts targeting NSP
SecRule ARGS_NAMES "@rx ^(url|redirect|next|return|dest|destination)$" \
    "chain,phase:2,deny,status:403,id:1004265,\
    msg:'Potential open redirect attempt (CVE-2026-40465)'"
    SecRule ARGS "@rx ^(https?:)?//(?!nsp\.example\.com)" \
        "t:none,t:lowercase"