CVE-2026-6606 Overview
A Server-Side Request Forgery (SSRF) vulnerability has been identified in ModelScope AgentScope versions up to 1.0.18. This vulnerability affects the _process_audio_block function within the file src/agentscope/agent/_agent_base.py. An attacker can manipulate the url argument to force the server to make unauthorized requests to internal or external resources. The attack can be launched remotely without authentication, making it a significant threat to deployments of this AI agent framework.
Critical Impact
Remote attackers can exploit this SSRF vulnerability to access internal network resources, bypass firewall restrictions, scan internal infrastructure, or potentially exfiltrate sensitive data from systems behind the AgentScope server.
Affected Products
- ModelScope AgentScope versions up to and including 1.0.18
- Systems running the vulnerable _agent_base.py component
- Deployments exposing AgentScope agents to untrusted network input
Discovery Timeline
- April 20, 2026 - CVE-2026-6606 published to NVD
- April 22, 2026 - Last updated in NVD database
Technical Details for CVE-2026-6606
Vulnerability Analysis
This SSRF vulnerability (CWE-918) resides in the audio processing functionality of the AgentScope AI agent framework. The _process_audio_block function accepts a URL parameter that is used to fetch audio resources without proper validation or sanitization. This allows attackers to supply arbitrary URLs, including those pointing to internal network addresses, cloud metadata endpoints, or other sensitive resources that should not be accessible from the application context.
The vulnerability is particularly concerning in cloud environments where access to metadata services (such as AWS IMDSv1 at 169.254.169.254) could lead to credential theft and further compromise of the infrastructure. The public availability of proof-of-concept exploit code increases the likelihood of active exploitation.
Root Cause
The root cause of this vulnerability is improper input validation in the _process_audio_block function. The url argument is processed without adequate checks to ensure it points only to legitimate, authorized external resources. The function fails to implement URL allowlisting, protocol restrictions, or network boundary enforcement, allowing attackers to manipulate the server into making requests on their behalf.
Attack Vector
This vulnerability is exploitable remotely over the network. An attacker can craft malicious input containing a controlled URL value, which is then passed to the _process_audio_block function. The server processes this URL and initiates a request to the attacker-specified destination. This can be leveraged to:
- Access internal services not exposed to the public internet
- Retrieve cloud provider metadata containing credentials
- Port scan internal network infrastructure
- Bypass IP-based access controls
- Exfiltrate data from internal resources through the vulnerable server
The exploitation does not require user interaction or authentication, as the function processes audio block URLs from incoming agent communications. A public proof-of-concept demonstrating this attack is available in the GitHub Gist PoC Repository.
Detection Methods for CVE-2026-6606
Indicators of Compromise
- Unusual outbound HTTP/HTTPS requests from AgentScope server to internal IP ranges (e.g., 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
- Requests to cloud metadata endpoints such as 169.254.169.254 or cloud-specific metadata URLs
- High volume of outbound requests to varied IP addresses or ports from the AgentScope process
- Network connections to unexpected localhost services (127.0.0.1) from the application
- Log entries showing URL processing for internal or restricted network resources
Detection Strategies
- Monitor application logs for _process_audio_block function invocations with suspicious URL patterns
- Implement network-level detection rules to alert on requests from AgentScope servers to internal IP ranges
- Deploy web application firewalls (WAF) with SSRF detection capabilities to filter malicious URL patterns
- Use SentinelOne Singularity to detect anomalous network behavior from Python processes associated with AgentScope
Monitoring Recommendations
- Enable verbose logging for the AgentScope agent framework to capture all URL processing events
- Configure network monitoring to track outbound connections from servers running AgentScope
- Set up alerts for access attempts to cloud metadata services from application servers
- Review firewall logs for denied outbound connections that may indicate exploitation attempts
How to Mitigate CVE-2026-6606
Immediate Actions Required
- Upgrade ModelScope AgentScope beyond version 1.0.18 when a patched version becomes available
- Implement network-level controls to block outbound requests from AgentScope servers to internal IP ranges
- Deploy a URL allowlist for the audio block processing functionality if application modification is possible
- Restrict AgentScope server network access using firewall rules to limit outbound connectivity
- For cloud deployments, enforce IMDSv2 to require session tokens for metadata access
Patch Information
As of the last update, the vendor (ModelScope) has not responded to disclosure attempts regarding this vulnerability. No official patch information is currently available. Organizations should monitor the VulDB Vulnerability #358241 entry and official ModelScope AgentScope repository for security updates.
Workarounds
- Implement an egress firewall blocking connections from the AgentScope server to private IP address ranges (RFC 1918)
- Deploy a forward proxy with URL filtering to intercept and validate all outbound requests from the application
- Modify the application code to implement URL validation using an allowlist approach before processing audio blocks
- Run AgentScope in an isolated network segment with restricted outbound connectivity
- Use cloud provider security groups to limit the instance's ability to reach metadata services
# Configuration example - iptables rules to block SSRF to internal networks
# Block access to private IP ranges from AgentScope server
iptables -A OUTPUT -d 10.0.0.0/8 -m owner --uid-owner agentscope -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -m owner --uid-owner agentscope -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -m owner --uid-owner agentscope -j DROP
iptables -A OUTPUT -d 169.254.169.254 -m owner --uid-owner agentscope -j DROP
iptables -A OUTPUT -d 127.0.0.0/8 -m owner --uid-owner agentscope -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
