CVE-2026-108719 in LLMGateway
Summary
by MITRE • 10/11/2026
LLMGateway through 1.20.0 contains a blind server-side request forgery vulnerability that allows API key holders to reach internal hosts via the video-generation callback_url extension. Attackers can supply loopback, private, or cloud-metadata URLs that deliverWebhook POSTs to without the assertSafeWebhookTarget check, reaching internal services from the worker's network.
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Analysis
by VulDB Data Team • 10/11/2026
The vulnerability identified in LLMGateway versions through 1.20.0 represents a critical server-side request forgery flaw rooted in insufficient validation of user-supplied input within the video-generation callback mechanism. This security defect specifically affects the handling of the callback_url parameter, which is intended to direct webhook POST requests to external endpoints for notification purposes. The core technical failure lies in the absence or bypass of the assertSafeWebhookTarget check during the processing of these URLs. Consequently, authenticated users possessing valid API keys can manipulate this field to redirect outbound network traffic from the application server toward internal infrastructure that should remain inaccessible from the public-facing interface. This lack of strict URL validation allows attackers to specify targets such as loopback addresses like 127.0.0.1 or localhost, private IP ranges including those defined in RFC 1918, and cloud metadata service endpoints which are typically restricted to internal network segments only.
From an operational perspective, this vulnerability enables a blind server-side request forgery attack where the attacker does not necessarily receive direct response data from the targeted internal services but can still exploit the connection for various malicious purposes. By directing webhook requests to internal hosts, attackers may attempt to interact with backend microservices, databases, or administrative interfaces that are protected by network-level security controls rather than application-layer authentication. This is particularly dangerous in cloud environments where metadata endpoints often contain sensitive information such as temporary credentials, IAM roles, and instance configuration details. An attacker could leverage this vector to exfiltrate these secrets, potentially escalating privileges within the cloud environment or compromising other services running on the same network segment. The blind nature of the attack means that detection may be delayed unless specific monitoring for outbound connections from application servers is in place.
This vulnerability aligns with Common Weakness Enumeration CWE-918, which addresses Server-Side Request Forgery (SSRF), specifically falling under subcategories related to insufficient validation of user-controlled input and bypassing security restrictions on internal network access. In the context of the MITRE ATT&CK framework, this exploit maps to techniques involving server-side request forgery for lateral movement or data exfiltration from cloud environments. The attack vector is classified as remote with low complexity but requires authentication via a valid API key, which places it within the scope of authenticated attacks that can lead to significant impact on confidentiality and integrity.
To mitigate this risk, immediate remediation involves upgrading LLMGateway to version 1.20.1 or later where the assertSafeWebhookTarget check has been properly implemented and enforced for all callback URLs. In addition to patching, organizations should implement strict allow-listing mechanisms for webhook destinations, ensuring that only pre-approved external domains are permitted for callback notifications. Network-level controls such as egress filtering on application servers can also provide a defense-in-depth strategy by blocking outbound connections to private IP ranges and cloud metadata endpoints unless explicitly required for legitimate business functions. Security teams should audit existing API key usage patterns and monitor logs for unusual outbound connection attempts originating from the LLMGateway service to detect any potential exploitation of this vulnerability in their environments.