CVE-2026-88403 in Nocobase
Summary
by MITRE • 09/22/2026
A Server-Side Request Forgery (SSRF) in the serverRequest function of nocobase v2.1.21 allows authenticated attackers to scan internal resources via a crafted HTTP request.
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Analysis
by VulDB Data Team • 09/22/2026
The vulnerability identified as an SSRF flaw within NocoBase version 2.1.21 represents a significant security risk for organizations deploying this open-source no-code platform, particularly in environments where the application is exposed to untrusted networks or has access to sensitive internal infrastructure. Server-Side Request Forgery occurs when a web server retrieves a specified resource from a URI provided by an end user without validating whether that destination should be trusted. In the specific context of NocoBase, this flaw resides within the serverRequest function, which is designed to facilitate HTTP requests on behalf of users or integrations. While such functionality is often necessary for building plugins, connecting external APIs, or performing webhook operations, it becomes dangerous when input validation and output encoding are insufficiently implemented. The core technical deficiency lies in the application's failure to properly sanitize or restrict the target URLs provided by authenticated users before initiating the outbound connection from the server side.
Because this vulnerability requires authentication, it is classified as an access-controlled SSRF rather than a blind or unauthenticated variant. This distinction implies that while attackers cannot exploit the flaw anonymously, they can leverage valid credentials obtained through phishing, credential stuffing, or other compromise methods to trigger internal network scans. Once authenticated, an attacker can craft HTTP requests with manipulated host parameters pointing toward private IP ranges such as 10.x.x.x, 172.16.x.x-172.31.x.x, or 192.168.x.x, which are typically inaccessible from the public internet. By analyzing the server's response codes and timing differences, attackers can perform port scanning and service enumeration against internal services that may include databases, administrative interfaces, cloud metadata endpoints like AWS EC2 instance metadata, or other microservices within the organization's network architecture.
The operational impact of this vulnerability extends beyond simple information disclosure. Successful exploitation allows an attacker to map out the internal network topology, identifying live hosts and open ports on critical infrastructure components. This reconnaissance phase is often a precursor to more severe attacks, such as exploiting known vulnerabilities in internal services that lack proper perimeter defenses. For instance, if NocoBase is deployed within a Kubernetes cluster or a cloud environment with access to metadata services, the SSRF could potentially be chained with other flaws to extract sensitive credentials or configuration data stored in these endpoints. The ability to interact with internal resources effectively bypasses network segmentation controls designed to isolate external-facing applications from backend systems, thereby undermining the principle of least privilege and defense-in-depth strategies employed by many security teams.
From a classification perspective, this vulnerability aligns closely with CWE-918, which defines Server-Side Request Forgery (SSRF) flaws where the web server makes requests based on user-supplied input without sufficient validation. It also maps to MITRE ATT&CK technique T1571, specifically the sub-category of Non-Standard Port or Protocol usage if attackers attempt to bypass firewalls by using unusual ports, and generally falls under Initial Access or Discovery phases depending on whether it is used for initial entry points or subsequent reconnaissance. The lack of strict allow-listing for destination hosts and protocols is a common pattern in SSRF vulnerabilities, highlighting the need for rigorous input validation mechanisms that restrict schemes to only HTTP and HTTPS while blocking internal IP ranges and localhost addresses.
Mitigation strategies must focus on implementing robust server-side controls to prevent unauthorized outbound connections. Developers should enforce an explicit allow-list of permitted domains or IP ranges rather than relying on blocklists, which are prone to bypasses through DNS rebinding attacks or encoding tricks. Additionally, the application should disable redirects by default or strictly validate redirect targets to ensure that even if a legitimate external domain returns a 3xx status code pointing to an internal resource, the request is not followed. Network-level mitigations such as egress filtering on firewalls can also reduce risk by blocking outbound connections from the NocoBase server to private IP ranges unless explicitly required for business logic. For organizations currently running version 2.1.21 or affected versions, upgrading to a patched release that addresses this specific flaw in the serverRequest function is the primary remediation step. Until an update can be applied, restricting user privileges and monitoring outbound traffic logs for anomalous connection attempts to internal subnets are recommended interim measures to detect potential exploitation activities.