CVE-2026-92576 in nanobot
Summary
by MITRE • 09/17/2026
HKUDS nanobot before 0.3.0 contains a server-side request forgery vulnerability in the WebFetchTool component where the _validate_url() function fails to block internal IP ranges and private addresses. Attackers can send messages instructing the bot to fetch cloud metadata endpoints, localhost services, and RFC 1918 addresses to extract IAM credentials and internal service data.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability identified in HKUDS nanobot versions prior to 0.3.0 represents a critical server-side request forgery flaw located within the WebFetchTool component. This security defect stems from an insufficient validation mechanism implemented by the _validate_url() function, which is responsible for sanitizing and verifying URLs before they are processed by the system. The core technical failure lies in the logic used to determine whether a requested URL points to an internal or external resource. Specifically, the implementation fails to adequately block access to private IP address ranges as defined by RFC 1918, such as those starting with 10.x.x.x, 172.16-31.x.x, and 192.168.x.x, as well as loopback addresses like localhost or 127.0.0.1. By not enforcing strict allow-listing of permitted external domains or properly rejecting internal network targets, the application inadvertently allows attackers to redirect outbound HTTP requests toward sensitive infrastructure endpoints that are otherwise inaccessible from the public internet.
From an operational perspective, this vulnerability enables adversaries to leverage the compromised nanobot as a proxy for accessing cloud metadata services and local host-based applications. Cloud providers typically expose instance metadata endpoints at well-known addresses such as 169.254.169.254 or similar variants depending on the provider environment. These endpoints contain highly sensitive information, including temporary security credentials, IAM roles, and configuration data necessary for authenticating with other cloud services. By instructing the bot to fetch these URLs, an attacker can retrieve valid access keys that may be used to escalate privileges within the cloud account. Furthermore, the ability to target localhost services allows attackers to interact with internal applications running on the same host as the nanobot, potentially exposing administrative interfaces or APIs that are not intended for external exposure.
This attack vector aligns closely with Common Weakness Enumeration CWE-918, which describes Server-Side Request Forgery (SSRF), specifically highlighting the failure to validate user-supplied URLs against a list of permitted domains and internal IP ranges. The exploitation technique also maps directly to MITRE ATT&CK tactic T1552.004, known as Cloud Instance Metadata API Credentials, where attackers target metadata services to steal credentials for lateral movement or privilege escalation within cloud environments. Additionally, the ability to scan local network resources falls under T1619, Cloud Infrastructure Discovery, indicating that this vulnerability can serve as an initial foothold for broader reconnaissance activities against internal infrastructure.
To mitigate this risk, immediate remediation should focus on updating HKUDS nanobot to version 0.3.0 or later, where the _validate_url() function has been hardened to properly reject requests targeting private IP ranges and loopback addresses. In cases where an upgrade is not immediately feasible, network-level controls such as firewall rules can be implemented to restrict outbound traffic from the host running the nanobot, preventing access to cloud metadata endpoints and internal service ports. Application-layer defenses should also include implementing a strict allow-list of permitted external domains for any URL fetching functionality, ensuring that no other destinations are accessible unless explicitly whitelisted. Regular security audits of input validation logic in web-fetching components are essential to prevent similar SSRF vulnerabilities from being introduced or persisting in future releases.