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Technical Deep Dive: CVE-2026-17623
CVE-2026-17623 is a critical OS command injection vulnerability discovered in IBM Langflow Open Source Software (OSS) versions 1.0.0 through 1.10.3. The flaw resides in the Model Context Protocol (MCP) server configuration component, specifically within the handling of the `command` field. Langflow uses MCP features to manage external server connections, project access, file resources, and local client integration. However, the application fails to properly validate and sanitize user-supplied input passed to the `command` parameter during MCP server configuration.
The vulnerability stems from inadequate validation mechanisms within the MCP server configuration components where the `command` field fails to properly sanitize or validate input parameters. When an authenticated user submits commands through the MCP interface, the system does not adequately filter or escape special characters that could be interpreted as shell commands by the underlying operating system. This improper validation creates a command injection pathway that allows attackers with legitimate authentication credentials to manipulate system processes through maliciously crafted command inputs.
The technical implementation of this flaw lies in the MCP server’s handling of user-supplied command parameters, which are processed without sufficient input validation or sanitization measures. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. This vulnerability aligns with CWE-78 (Improper Neutralization of Special Elements used in an OS Command) and CWE-94 (Improper Control of Generation of Code) categories.
The attack can be launched remotely over the network and requires low privileges and low attack complexity. The flaw operates at the application layer and can be exploited through authenticated sessions, making it particularly dangerous in environments where legitimate user credentials might be compromised or when privilege escalation occurs. Successful exploitation could allow attackers to execute malicious commands with the privileges of the affected application process, potentially leading to full system compromise, data exfiltration, or lateral movement within network environments. The vulnerability has been assigned a CVSS Base Score of 8.8 (High) by IBM, with the vector (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
DailyCVE Form:
Platform: IBM Langflow OSS
Version: 1.0.0–1.10.3
Vulnerability: OS Command Injection
Severity: Critical (CVSS 8.8)
date: 2026-08-05
Prediction: 2026-08-20
What Undercode Say: Analytics
Check Langflow version
langflow --version
Verify MCP server configuration endpoints
curl -X GET http://target:7860/api/v1/mcp/config -H "Authorization: Bearer <token>"
Test for command injection in command field (authenticated)
curl -X POST http://target:7860/api/v1/mcp/server \
-H "Authorization: Bearer <token>" \
-H "Content-Type: application/json" \
-d '{"name": "test", "command": "id; whoami"}'
Monitor for unusual command execution patterns in logs
grep -i "mcp.command" /var/log/langflow/.log | grep -E "(;|||&|\$(|<code>)"
List running processes for suspicious activity
ps aux | grep -E "(langflow|mcp)" | grep -v grep
Check for unauthorized file modifications
find /opt/langflow -type f -mtime -1 -exec ls -la {} \;
<h2 style=”color: blue;”>Exploit:</h2>
The vulnerability can be exploited by an authenticated attacker with network access to the Langflow MCP server configuration endpoint. The attacker crafts a malicious `command` field value containing shell metacharacters (e.g.,;,|,&&,$(), backticks) to inject arbitrary OS commands. These commands are executed with the privileges of the Langflow server process. Example payload: `"command": " legitimate_cmd; malicious_cmd"` or“command”: “$(malicious_cmd)”`. No public exploit is currently available, but technical details are known and the attack is considered easy to execute. The estimated exploit price ranges from $5,000 to $25,000.
Protection:
- Upgrade to a patched version of IBM Langflow OSS beyond 1.10.3 immediately.
- Implement network segmentation to limit access to MCP server components.
- Enforce strict input validation and sanitization for all `command` field inputs at all application interfaces.
- Apply the principle of least privilege for user accounts accessing MCP configurations.
- Deploy Web Application Firewalls (WAF) to detect and block suspicious command injection attempts.
- Monitor authentication logs for unusual command execution patterns.
- Consider disabling MCP features if not required until a patch is applied.
Impact:
Successful exploitation allows a remote authenticated attacker to execute arbitrary commands on the affected system with the privileges of the Langflow application process. This can lead to full system compromise, including data exfiltration, unauthorized file access, privilege escalation, lateral movement within the network, and complete loss of confidentiality, integrity, and availability. The vulnerability is particularly dangerous in cloud environments or containerized deployments where Langflow may run with elevated privileges. The attack requires low privileges and low complexity, making it highly accessible to attackers.
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Sources:
Reported By: nvd.nist.gov
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