OpenClaw < 2026.4.20 - Arbitrary Code Execution via MCP stdio Environment Variables
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.4epss 0.1%
exploitation probability
0.1%top 96% of all CVEs
observed exploitation
nono source reports it
OpenClaw before 2026.4.20 contains an improper environment variable validation vulnerability in MCP stdio server configuration that allows attackers to execute arbitrary code. Malicious workspace configurations can pass dangerous startup variables like NODE_OPTIONS, LD_PRELOAD, or BASH_ENV to spawned MCP server processes, enabling code injection when operators start sessions using those servers.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
OpenClaw · OpenClawReferences
https://github.com/openclaw/openclaw/commit/62fa5071896e95edc7f67d1cebc70a2859e283afhttps://github.com/openclaw/openclaw/commit/85d86ebc4bf3d2226d39d132a484f4f7a299fa1bhttps://github.com/openclaw/openclaw/security/advisories/GHSA-mj59-h3q9-ghfhhttps://www.vulncheck.com/advisories/openclaw-arbitrary-code-execution-via-mcp-stdio-environment-variables