CVE-2026-4039 — openclaw
Fix: openclaw/openclaw@8c9f35cCVE-2026-4039 is a CWE-74 vulnerability in openclaw. A fix is available for openclaw — see the affected versions and patch details below.
OpenClaw Skill Env applySkillConfigenvOverrides code injection
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-4039.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
openclawnpmDescription
Summary
applySkillConfigEnvOverrides previously copied skills.entries.*.env values into the host process.env without applying the host env safety policy.
Impact
In affected versions, dangerous process-level variables such as NODE_OPTIONS could be injected when unset, which can influence runtime/child-process behavior.
Required attacker capability
An attacker must be able to modify OpenClaw local state/config (for example ~/.openclaw/openclaw.json) to set skills.entries.<skill>.env or related skill config values.
Remediation
Fixed in 2026.2.21 by sanitizing skill env overrides and blocking dangerous host env keys (including NODE_OPTIONS) before applying overrides, with regression tests covering blocked dangerous keys.
Fix Commit(s)
8c9f35cdb51692b650ddf05b259ccdd75cc9a83c
Found using MCPwner
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | openclaw | all versions | 2026.2.21npm install openclaw@2026.2.21 |
Affected Products
openclawopenclawDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openclaw, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openclaw to 2026.2.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-4039 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-4039 in your dependencies?
Find it across npm, including transitive dependencies.