CVE-2026-75856 in CodeWhale
Summary
by MITRE • 08/18/2026
CodeWhale before 0.8.64 contains a server-side request forgery bypass vulnerability in DNS pinning logic that fails to prevent time-of-check-time-of-use attacks. Attackers can manipulate DNS responses to fail initial resolution checks and succeed on secondary requests, allowing requests to internal IP addresses and bypassing SSRF mitigations.
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Analysis
by VulDB Data Team • 08/18/2026
The identified vulnerability resides within the DNS pinning implementation of CodeWhale versions prior to 0.8.64, representing a critical failure in server-side request forgery mitigation strategies. The core technical flaw is rooted in a time-of-check-to-time-of-use race condition inherent in how the application validates and caches domain name resolutions. When an outbound connection is initiated, the system performs an initial DNS lookup to verify that the target hostname resolves to a safe, external IP address. However, this validation check is not permanently bound or pinned for the duration of the network session. Instead, subsequent requests within the same logical operation may trigger new DNS lookups rather than strictly adhering to the initially resolved IP address. This architectural oversight creates a window of opportunity where an attacker can manipulate the Domain Name System responses between the initial verification step and the actual data transmission phase.
From an operational perspective, this flaw allows for sophisticated server-side request forgery attacks that bypass standard SSRF protections designed to restrict access to internal network resources or cloud metadata services. By exploiting DNS rebinding techniques, an adversary can configure a malicious domain such that its first DNS response returns a safe public IP address, thereby passing the initial security check performed by CodeWhale. Subsequently, before the application completes its request processing and sends data, the attacker alters the DNS record to resolve to a private internal IP address, such as 127.0.0.1 or an internal subnet range like 192.168.x.x. Because the application performs fresh lookups for subsequent interactions rather than locking onto the initial safe resolution, it unknowingly directs traffic toward sensitive internal infrastructure. This mechanism effectively neutralizes perimeter-based SSRF filters that rely solely on static IP validation at the point of initiation.
This vulnerability aligns with CWE-345, which describes Insufficient Verification of Data Authenticity, specifically highlighting the failure to maintain consistency between initial checks and subsequent actions. It also maps directly to MITRE ATT&CK technique T1071.004, Application Layer Protocol: DNS, as it leverages DNS manipulation for evasion. Furthermore, the exploitation pattern corresponds to CWE-367, Time-of-check Time-of-use Race Condition, underscoring the temporal gap between validation and execution that makes this attack vector viable. The impact of such an exploit can be severe, potentially leading to unauthorized access to internal APIs, extraction of sensitive metadata from cloud environments like AWS or Azure, or lateral movement within a protected network segment by interacting with services that are not exposed to the public internet but are accessible via local host loops.
To mitigate this risk, organizations running CodeWhale versions earlier than 0.8.64 must upgrade immediately to version 0.8.64 or later, where the DNS pinning logic has been corrected to enforce strict adherence to the initially resolved IP address throughout the entire request lifecycle. In environments where immediate patching is not feasible, defensive measures should include implementing network-level controls such as egress filtering that blocks outbound connections to private IP ranges regardless of hostname resolution. Additionally, deploying a reverse proxy with robust SSRF protection capabilities can help intercept and validate outgoing requests before they reach the vulnerable application component. Security teams should also monitor for anomalous DNS query patterns originating from CodeWhale instances, particularly those involving rapid changes in resolved IPs or queries targeting internal address spaces, as these may indicate active exploitation attempts of this race condition vulnerability.