CVE-2026-31231: Cognee RCE Vulnerability via exec()

CVE-2026-31231 Overview

CVE-2026-31231 is a remote code execution vulnerability in Cognee through version v0.4.0. The flaw resides in the notebook cell execution API endpoint, which passes user-supplied Python code directly to the unsafe exec() function. The endpoint lacks sandboxing, input validation, and authentication controls. An unauthenticated attacker can send a crafted POST request containing arbitrary Python code and achieve full code execution on the Cognee server. The classification falls under [CWE-94] Improper Control of Generation of Code (Code Injection).

Critical Impact

Unauthenticated attackers can execute arbitrary Python code remotely with the server process privileges, leading to complete system compromise.

Affected Products

• Cognee through v0.4.0
• Cognee notebook cell execution API endpoint
• Self-hosted Cognee deployments exposing the affected endpoint

Discovery Timeline

• 2026-05-12 - CVE-2026-31231 published to NVD
• 2026-05-15 - Last updated in NVD database

Technical Details for CVE-2026-31231

Vulnerability Analysis

The vulnerability stems from the Cognee notebook cell execution API endpoint that accepts arbitrary Python source code from clients. The handler dispatches the supplied code directly to Python's built-in exec() function. The endpoint enforces no authentication, no allow-list of permitted statements, and no isolation boundary such as a container or restricted interpreter.

Because exec() runs in the same process context as the Cognee server, any code submitted gains the full privileges of that process. An attacker can import modules such as os, subprocess, or socket to spawn shells, exfiltrate data, or pivot inside the network. The vulnerability is reachable over the network without user interaction.

Cognee is an AI memory and knowledge-graph framework, so affected hosts often store sensitive embeddings, API keys for upstream language model providers, and ingested corporate data. Successful exploitation exposes all of that material to the attacker.

Root Cause

The root cause is the direct use of exec() on untrusted input. The notebook feature was designed to evaluate user-supplied Python cells, but the implementation treats the network-exposed endpoint as if it were a local trusted REPL. No interpreter sandbox, seccomp profile, or namespace isolation guards the call.

Attack Vector

The attack vector is network-based. An attacker issues an HTTP POST request to the notebook execution endpoint with a JSON body containing Python code. The server passes the body to exec(), and the payload runs immediately. Because no credentials are required, any actor with network reachability to the Cognee instance can exploit the flaw.

Technical details are described in the Cognee GitHub project repository and the public CVE-2026-31231 write-up. No verified public exploit code is referenced in the advisory.

Detection Methods for CVE-2026-31231

Indicators of Compromise

• POST requests to the Cognee notebook cell execution endpoint containing Python keywords such as import os, subprocess, eval, or __import__ in the request body.
• Child processes spawned by the Cognee server process, particularly sh, bash, python, curl, or wget.
• Outbound network connections initiated by the Cognee process to unfamiliar external hosts.
• New or modified files in Cognee working directories that were not created by legitimate notebook activity.

Detection Strategies

• Inspect HTTP request bodies to the notebook execution endpoint and flag payloads containing dynamic code constructs or shell utilities.
• Baseline the legitimate process tree of the Cognee server and alert on any unexpected child process execution.
• Correlate API access logs with process and network telemetry from the host running Cognee to identify post-exploitation activity.

Monitoring Recommendations

• Forward Cognee application logs, web server access logs, and host process telemetry to a centralized analytics platform for correlation.
• Monitor for credential access patterns such as reads of .env, cloud metadata endpoints, or SSH key files from the Cognee process.
• Track egress traffic from Cognee hosts and alert on connections to non-allow-listed destinations.

How to Mitigate CVE-2026-31231

Immediate Actions Required

• Remove network exposure of the Cognee notebook execution endpoint until a fixed release is deployed.
• Restrict access to the Cognee service to trusted networks using firewall rules or reverse-proxy authentication.
• Audit Cognee hosts for signs of prior exploitation, including unexpected processes, files, and outbound connections.
• Rotate any credentials, API tokens, or model provider keys accessible to the Cognee process.

Patch Information

No fixed version is referenced in the published advisory at the time of writing. Monitor the Cognee GitHub project repository for security releases and upgrade beyond v0.4.0 once a patched version is available.

Workarounds

• Disable the notebook cell execution feature or remove the route from the deployed configuration.
• Place the Cognee service behind an authenticating reverse proxy that blocks unauthenticated POST requests to the execution endpoint.
• Run Cognee inside a hardened container with a non-root user, read-only filesystem, and restrictive seccomp and network egress policies to limit blast radius.
• Apply a Web Application Firewall rule that rejects request bodies containing Python code constructs targeting the notebook endpoint.

# Configuration example: block external access to the notebook execution endpoint
# Example nginx snippet placed in front of Cognee
location /api/v1/notebook/execute {
    allow 10.0.0.0/8;     # internal management network only
    deny all;
    proxy_pass http://cognee_upstream;
}