Summary
PraisonAI vulnerable to Remote Code Execution via Broken AST Sandbox
JobWorkflowExecutor._exec_inline_python() is designed to safely execute inline Python expressions from YAML workflow script: steps using AST validation. The function claims to block dangerous operations by (a) checking all AST nodes against an allowlist, and (b) providing a builtins whitelist that omits import, exec, eval, and open.
The sandbox is broken. The module import allowlist (allowed_modules) explicitly includes 'os', and the AST allowlist permits ast.Import, ast.ImportFrom, ast.Call, and ast.Attribute nodes. This means the following malicious workflow script: step passes all AST validation checks and executes without error.
Attack Scenario
Attacker creates or contributes a YAML workflow file (type: job) with a script: step containing import os; os.system(...).
A user or CI pipeline with PRAISONAI_ALLOW_JOB_WORKFLOWS=true executes the workflow via praisonai workflow run malicious.yaml.
Arbitrary OS commands execute with the privileges of the calling process.
This is particularly dangerous in multi-tenant or CI environments where YAML workflows may originate from untrusted sources (e.g., downloaded templates, shared repositories, AI-generated workflows).
PoC
Complete instructions, including specific configuration details, to reproduce the vulnerability.
Output: SANDBOX BYPASSED
AFTER (safe)
allowed_modules = {'datetime', 'time', 'json', 'math', 're', 'collections', 'itertools', 'pathlib'}
If os.path is needed, handle it explicitly:
if isinstance(node, ast.ImportFrom):
if node.module == 'os.path':
pass # allow 'from os.path import join, exists' only
elif node.module and node.module.split('.')[0] not in allowed_modules:
return {"ok": False, "error": f"Import of '{node.module}' not allowed."}
Additionally, block ast.Import of os entirely, and consider also removing re (which can be used for ReDoS/CPU exhaustion) and collections (which can be used to reach subclasses-style gadgets).
Impact
Root Cause, Lines 364–372:
pythonallowed_modules = {'os', 'datetime', 'time', 'json', 'math', 're', 'collections', 'itertools'}
if isinstance(node, ast.Import):
for alias in node.names:
if alias.name.split('.')[0] not in allowed_modules:
return {"ok": False, "error": f"Import of '{alias.name}' not allowed..."}
os is trusted because it is commonly used for path operations (os.path, os.getcwd). However, os.system(), os.popen(), os.execvp(), os.spawn*(), and os._exit() are all accessible once the module is imported, none of which are individually blocked.
The builtins restriction (blocking import) is irrelevant because the code uses a real import statement processed by the Python bytecode compiler, not a import() call.
Proof-of-Concept validation (static, no remote network call made):
pythonimport ast
_ALLOWED_NODES = (
ast.Expression, ast.BoolOp, ast.BinOp, ast.UnaryOp, ast.Compare,
ast.IfExp, ast.Constant, ast.Name, ast.Load, ast.Store, ast.Subscript,
ast.List, ast.Tuple, ast.Dict, ast.Set,
ast.And, ast.Or, ast.Not, ast.Eq, ast.NotEq, ast.Lt, ast.LtE,
ast.Gt, ast.GtE, ast.In, ast.NotIn, ast.Add, ast.Sub, ast.Mult,
ast.Div, ast.Mod, ast.FloorDiv, ast.USub, ast.UAdd,
ast.Call, ast.Attribute, ast.keyword, ast.Starred,
ast.Module, ast.Assign, ast.Import, ast.ImportFrom, ast.alias,
)
allowed_modules = {'os', 'datetime', 'time', 'json', 'math', 're', 'collections', 'itertools'}
malicious = "import os\nresult = os.system('id')"
tree = ast.parse(malicious, mode="exec")
all_pass = True
for node in ast.walk(tree):
if not isinstance(node, _ALLOWED_NODES):
print(f"BLOCKED: {type(node).name}")
all_pass = False
if isinstance(node, ast.Import):
for alias in node.names:
if alias.name.split('.')[0] not in allowed_modules:
print(f"IMPORT BLOCKED: {alias.name}")
all_pass = False
print("SANDBOX BYPASSED" if all_pass else "sandbox holds")
Untrusted input reaches a shell command, allowing arbitrary commands to run on the host. Typical impact: code execution in the application's environment.
CVE-2026-61438 has a CVSS score of 7.3 (High). The vector is requires local access, low 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. A fixed version is available (4.6.78); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Remove 'os' from allowed_modules and replace it with only the safe submodule: 'os.path'. Then validate that the imported name is specifically os.path, not os:
python# BEFORE (vulnerable)
allowed_modules = {'os', 'datetime', 'time', 'json', 'math', 're', 'collections', 'itertools'}
Frequently Asked Questions
- What is CVE-2026-61438? CVE-2026-61438 is a high-severity OS command injection vulnerability in praisonai (pip), affecting versions < 4.6.78. It is fixed in 4.6.78. Untrusted input reaches a shell command, allowing arbitrary commands to run on the host.
- How severe is CVE-2026-61438? CVE-2026-61438 has a CVSS score of 7.3 (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.
- Which versions of praisonai are affected by CVE-2026-61438? praisonai (pip) versions < 4.6.78 is affected.
- Is there a fix for CVE-2026-61438? Yes. CVE-2026-61438 is fixed in 4.6.78. Upgrade to this version or later.
- Is CVE-2026-61438 exploitable, and should I be worried? Whether CVE-2026-61438 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
- What actually determines whether CVE-2026-61438 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.
- How do I fix CVE-2026-61438? Upgrade
praisonaito 4.6.78 or later.