CVE-2026-82477 in Heimdall
Summary
by MITRE • 08/29/2026
In MITRE SAF Heimdall 2.11.6 through 2.13.x before 2.14.0, an SSRF issue allows remote attackers to access internal network resources via the Tenable proxy endpoint. This occurs in apps/backend/src/tenable/tenable.controller.ts.
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Analysis
by VulDB Data Team • 08/29/2026
The vulnerability identified within MITRE SAF Heimdall versions ranging from 2.11.6 through 2.13.x prior to version 2.14.0 represents a critical Server-Side Request Forgery (SSRF) flaw located specifically in the application logic of apps/backend/src/tenable/tenable.controller.ts. This component serves as an intermediary for proxying requests, likely facilitating communication between the Heimdall interface and Tenable security scanning infrastructure. The core technical deficiency lies in the insufficient validation and sanitization of user-supplied input directed toward this proxy endpoint. When a remote attacker constructs a malicious request containing a specifically crafted URL or IP address targeting internal network resources, the application fails to adequately restrict the destination scope. Consequently, the server processes the external request on behalf of the client, effectively acting as an open relay that can reach services and endpoints residing within the private network topology behind Heimdall.
From a technical perspective, this SSRF vulnerability allows for unauthorized access to internal resources that are typically not exposed to the public internet or untrusted networks. The attacker leverages the trusted relationship between the application server and its backend dependencies to bypass perimeter security controls such as firewalls and intrusion detection systems. By manipulating the proxy endpoint, an adversary can probe internal services, attempt to exploit other vulnerabilities on local hosts, or access sensitive configuration files and administrative interfaces that reside within the same network segment. This capability transforms a seemingly benign web application feature into a powerful tool for lateral movement and reconnaissance within the target environment.
The operational impact of this vulnerability is significant, particularly in environments where Heimdall is deployed as part of a broader security operations workflow. Successful exploitation could lead to the disclosure of sensitive internal data, including credentials stored on local services, network topology details, or proprietary information hosted by internal applications. Furthermore, attackers may use this foothold to pivot into more critical systems within the organization's infrastructure, potentially leading to full system compromise. In cloud-native deployments, SSRF vulnerabilities can also be leveraged to access instance metadata endpoints, such as those provided by AWS EC2 or Azure Managed Identity services, which often contain temporary security credentials that grant elevated privileges across cloud resources.
This vulnerability aligns with CWE-918, Server-Side Request Forgery (SSRF), specifically falling under the sub-category of weak URL validation where user input is directly used to construct outbound requests without proper allow-listing or domain restriction mechanisms. In terms of offensive security tactics, this exploit maps to MITRE ATT&CK technique T1571, which covers Non-Standard Ports and protocols often exploited in SSRF scenarios, as well as T1098, Account Manipulation if the attacker uses accessed credentials for persistent access. The lack of strict output control on proxy destinations is a common pattern in web applications that integrate with third-party services without implementing robust security boundaries around those integrations.
To mitigate this vulnerability, organizations must immediately upgrade to MITRE SAF Heimdall version 2.14.0 or later, where the issue has been addressed through improved input validation and stricter proxying policies. For environments unable to patch immediately, defensive measures should include configuring network-level controls such as firewall rules to restrict outbound connections from the application server to only known and necessary internal endpoints. Implementing a reverse proxy with strict allow-lists for permitted domains can also prevent access to private IP ranges or cloud metadata services. Additionally, deploying Web Application Firewalls (WAF) with specific signatures capable of detecting SSRF patterns in HTTP requests may provide an additional layer of defense by blocking malicious payloads before they reach the vulnerable application logic. Regular security assessments and code reviews focusing on proxy implementations are recommended to prevent similar issues in future development cycles.