Openclaw cli: OpenClaw: Incomplete host-env-security-policy allows untrusted model to substitute compiler binaries via env overrides (CVE-2026-41373)

The OpenClaw CLI's host-env-security-policy.json prior to version 2026.3.31 does not fully restrict environment variable overrides for compiler binaries such as CC, CXX, CARGO_BUILD_RUSTC, and CMAKE_C_COMPILER. This incomplete policy allows an untrusted model, when executing within an approved host-exec request, to substitute these compiler binaries via environment overrides. Exploitation requires an existing approved host-exec request within the trusted execution domain, limiting the scope of the vulnerability. The issue was fixed in commit e277a37f896b5011a1df06e6490c6630074d0afa and patched in OpenClaw CLI version 2026.3.31.

An attacker with the ability to submit an approved host-exec request can substitute compiler binaries via environment variable overrides, potentially leading to high integrity impact by executing malicious compiler binaries. Confidentiality impact is low and availability is not affected. The vulnerability is rated medium severity with a CVSS score of 6.1.

Upgrade OpenClaw CLI to version 2026.3.31 or later, which includes the fix for this incomplete host environment security policy. The patch restricts environment variable overrides for compiler binaries to prevent substitution attacks. No additional mitigation is required if the upgrade is applied.