CVE-2026-105647 in Ghost
Summary
by MITRE • 10/06/2026
Ghost is a Node.js content management system. From 6.54.1 until 6.65.0, a validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network. A successful attack would not result in any response data being returned. This issue is fixed in version 6.65.0.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified within the Ghost content management system, specifically affecting versions from 6.54.1 through 6.65.0, represents a significant server-side request forgery risk that exploits insufficient input validation mechanisms. As an open-source publishing platform built on Node.js, Ghost handles various external integrations and webhook functionalities, including Webmentions which are used to acknowledge references or replies from other websites. The core technical flaw lies in the handling of these incoming requests where the system fails to adequately validate or restrict the destination hosts for outbound HTTP connections initiated by features like Webmention processing. This lack of strict allow-listing or domain validation allows an unauthenticated actor to manipulate the request parameters, effectively turning the Ghost server into a proxy that can reach internal network resources which would otherwise be inaccessible from the public internet.
From a technical perspective, this vulnerability aligns with CWE-918, Server-Side Request Forgery (SSRF), specifically where the weakness involves insufficient validation of user-supplied input used to construct outbound requests. The attacker does not need valid credentials or prior authentication because the vulnerable endpoint is exposed publicly and processes inputs without verifying if the target host resides within a trusted range or external whitelist. By crafting specific HTTP requests, an adversary can direct the Ghost server to communicate with internal services such as database interfaces, administrative panels, or other microservices running on localhost or private IP ranges associated with the hosting infrastructure. This capability is particularly dangerous in containerized environments or cloud deployments where multiple services share network segments and rely on perimeter defenses rather than strict host-based access controls for inter-service communication.
The operational impact of this vulnerability is nuanced due to its limited data exfiltration capabilities, yet it remains critical from a security posture perspective. While the description notes that no response data is returned directly to the attacker, meaning traditional blind SSRF techniques cannot be used to read sensitive content via side channels like DNS or HTTP callbacks in the same way as other variants, the ability to probe internal services can still lead to severe consequences. An attacker could use this vector for network reconnaissance, mapping out internal service architectures and identifying open ports or running versions of software that may harbor their own vulnerabilities. Furthermore, if any internal service has its own authentication bypasses or misconfigurations, the forged request from a trusted source like the Ghost server might successfully authenticate against those services, potentially leading to unauthorized access or further exploitation chains. This effectively undermines the principle of least privilege and network segmentation strategies intended to isolate critical backend components from public-facing applications.
Mitigation for this issue requires immediate action by upgrading the Ghost installation to version 6.65.0 or later, where the validation logic has been corrected to enforce stricter controls on outbound connections. In addition to patching, organizations should implement defense-in-depth strategies such as network segmentation to ensure that even if an SSRF vulnerability is exploited in a public-facing application, it cannot reach sensitive internal resources. Utilizing web application firewalls with rulesets designed to detect and block suspicious outbound traffic patterns can also provide an additional layer of protection. It is advisable for administrators to audit their deployment configurations to minimize the attack surface by disabling unnecessary integrations like Webmentions if they are not actively used, thereby reducing the potential entry points available to unauthenticated attackers seeking to leverage server-side request forgery vectors against internal infrastructure.