OpenClaw's shell env fallback trusts unvalidated SHELL path from host environment

The shell environment fallback path could invoke an attacker-controlled shell when SHELL was inherited from an untrusted host environment. In affected builds, shell-env loading used $SHELL -l -c 'env -0' without validating that SHELL points to a trusted executable.

In threat-model terms, this requires local environment compromise or untrusted startup environment injection first; it is not a remote pre-auth path. The hardening patch validates SHELL as an absolute normalized executable, prefers /etc/shells, applies trusted-prefix fallback checks, and falls back safely to /bin/sh when validation fails. The dangerous env-var policy now also blocks SHELL overrides.

Affected Packages / Versions

• Package: openclaw (npm)
• Affected versions: <= 2026.2.21-2
• Latest published vulnerable version: 2026.2.21-2
• Patched versions (planned next release): >= 2026.2.22

Fix Commit(s)

• 25e89cc86338ef475d26be043aa541dfdb95e52a

Release Process Note

The advisory pre-sets patched_versions to the planned next release (2026.2.22). After that npm release is published, maintainers can publish this advisory without further version-field edits.

OpenClaw thanks @athuljayaram for reporting.