CVE-2026-86100 in Camaleon CMS
Summary
by MITRE • 09/05/2026
Camaleon CMS versions 2.7.5 through 2.9.1 fail to validate redirect targets when fetching remote files in the Upload from URL media feature. Authenticated attackers can supply URLs that pass initial validation but redirect to internal network addresses, allowing server-side request forgery to internal services.
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Analysis
by VulDB Data Team • 09/05/2026
The vulnerability identified in Camaleon CMS versions 2.7.5 through 2.9.1 represents a critical security flaw within the media management subsystem, specifically affecting the Upload from URL feature. This functionality allows authenticated users to specify remote file locations for ingestion into the system's content repository. The core technical deficiency lies in the application’s handling of HTTP redirections during the fetch process. While the initial validation mechanism may correctly verify that a provided Uniform Resource Identifier conforms to expected protocols and formats, it fails to inspect or restrict subsequent redirect targets. This oversight creates an opportunity for Server-Side Request Forgery, where the server itself is coerced into making requests to destinations chosen by the attacker rather than the originally intended target.
From a technical perspective, this flaw exploits the standard behavior of HTTP clients which automatically follow redirects unless explicitly configured otherwise. When an authenticated user submits a URL that points to an external resource controlled by them, they can configure that resource to return an HTTP redirect status code pointing toward an internal network address. Because Camaleon CMS does not validate these final destinations against a whitelist or enforce strict domain restrictions on the resolved endpoint, it proceeds with fetching data from the internal IP addresses. This effectively bypasses perimeter security controls and allows the application server to act as a proxy for accessing services that are otherwise inaccessible from the public internet.
The operational impact of this vulnerability is significant due to its potential to facilitate lateral movement within an organization’s network infrastructure. An authenticated attacker can leverage this flaw to probe internal services, such as database servers, administrative interfaces, or other microservices running on private IP ranges. By analyzing the response codes and content returned by these internal endpoints, the attacker can gather sensitive information about the internal architecture, identify vulnerable systems, and potentially escalate privileges further within the environment. This capability undermines the principle of network segmentation, allowing threats to traverse from a web-facing application into protected backend networks without requiring direct external access to those resources.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-918, which describes Server-Side Request Forgery (SSRF). The flaw is characterized by insufficient validation of user-supplied input that influences server-side network requests. Furthermore, in the context of the MITRE ATT&CK framework, this behavior corresponds to techniques involving Taint Analysis and Data from Information Repositories, as well as potential exploitation paths under Remote Services if internal services are compromised. The lack of strict output encoding or destination validation allows for indirect attacks that can lead to data exfiltration or further system compromise.
To mitigate this risk, immediate action is required to update Camaleon CMS to a version where the redirect handling logic has been hardened. Developers should implement strict allow-listing mechanisms for permitted domains and IP ranges when fetching remote files. Additionally, configuring HTTP clients to disable automatic redirections entirely during file ingestion processes can prevent attackers from leveraging redirects to reach internal targets. Network-level controls such as egress filtering on the application server’s network interface can also serve as a defense-in-depth measure by blocking outbound connections to private IP address spaces that are not explicitly required for business operations. Regular security audits of media upload features and continuous monitoring for anomalous outbound traffic patterns will further enhance resilience against this class of vulnerabilities.