CVE-2026-55673

Description

Both AbstractLocalCommandExecutor OS-dependent implementations are subject to CWE-78 (OS Command Injection), with a secondary CWE-88 (Argument Injection) concern via environment variables.

The local command executor build command strings via concatenation and executes them (through bash -c for Unix, or cmd /c for Windows). Any string argument or environment variable value reaching this executor can break out of the intended command and execute arbitrary shell code as the JVM user.

The sink is reachable through public APIs that accept List<String> arguments without any documented indication that elements undergo shell interpretation.

Any caller, CLI, library integration, or embedding service, that forwards data from a less-trusted source into these APIs inherits the vulnerability.

Vulnerable elements

The vulnerable elements are:

• Public methods:
  • UnixLocalCommandExecutor.execute(...)
  • WindowsLocalCommandExecutor.execute(...)
  • LocalComputationManager.execute(...)
  • ParallelLoadFlowActionSimulator.run(...)
  • ActionSimulatorTool.run(...)
  • AmplModelRunner.run(...)
  • AmplModelRunner.runAsync(...)
• itools commands:
  • action-simulator, when the task-count option is defined
  • security-analysis, when the external option is defined
  • dynamic-security-analysis

Characteristics

The vulnerability characteristics are the following:

• It allows arbitrary shell command execution as the JVM user (read, write, execute any file; spawn processes; exfiltrate data; etc.)
• There are multiple independent injection vectors within a single vulnerable call:
  • args elements (weakly escaped, bypassable via $(...), backticks, escaped quotes)
  • Environment variable values (unescaped, bypassable via ;, \n, or shell metacharacters)
• It is silent from the caller's perspective: the List<String> API gives no indication that shell interpretation occurs.
• It exposes downstream projects: any service embedding powsybl-core (REST front-ends, pypowsybl tooling, multi-tenant grid analysis platforms) that exposes contingency IDs or computation parameters to external input is exploitable without needing to touch powsybl's code directly.

Am I impacted?

You are vulnerable if you make direct calls to one of the vulnerable end-user methods or itools commands listed in the "Vulnerable elements" section, with user-provided parameters, without controlling them.

Workarounds

If you cannot update your powsybl-computation-local version, you can check the content of the user-provided arguments when calling the vulnerable methods, by forbidding (if possible) the following characters:

• On Unix/Linux systems:
  • \, !, #, $, ^, &, *, (, ), {, }, |, [, ], \, ;, \, ", ,, <, >, ?,
• On Windows:
  • %, !, ", \n, \r, ^