GHSA-82g8-464f-2mv7 CVE-2026-4039
OpenClaw: Skill env override host env injection via applySkillConfigEnvOverrides (defense-in-depth)
High
npm
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.33%
- Chance of exploitation in the next 30 days. Higher than 26.05% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-1341 Multiple Releases of Same Resource or Handle
- CWE-15 External Control of System or Configuration Setting
- CWE-94 Improper Control of Generation of Code ('Code Injection')
- Fix
2026.2.21- Upgrade openclaw to this version or later
Description
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 versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| openclaw | < 2026.2.21 |
2026.2.21 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
openclaw npm → 2026.2.21
- npm
npm install openclaw@2026.2.21- yarn
yarn add openclaw@2026.2.21- pnpm
pnpm add openclaw@2026.2.21
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- High
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.1 8.8
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-1341: Multiple Releases of Same Resource or Handle
The product attempts to close or release a resource or handle more than once, without any successful open between the close operations.
How to prevent it
- Implementation: Change the code's logic so that the resource is only closed once. This might require simplifying or refactoring. This fix can be simple to do in small code blocks, but more difficult when multiple closes are buried within complex conditionals.
- Implementation: It can be effective to implement a flag that is (1) set when the resource is opened, (2) cleared when it is closed, and (3) checked before closing. This approach can be useful when there are disparate cases in which closes must be performed. However, flag-tracking can increase code complexity and requires diligent compliance by the programmer.
- Implementation: When closing a resource, set the resource's associated variable to NULL or equivalent value for the given language. Some APIs will ignore this null value without causing errors. For other APIs, this can lead to application crashes or exceptions, which may still be preferable to corrupting an unintended resource such as memory or data.
CWE-15: External Control of System or Configuration Setting
One or more system settings or configuration elements can be externally controlled by a user.
How to prevent it
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
- Implementation, Architecture and Design: Because setting manipulation covers a diverse set of functions, any attempt at illustrating it will inevitably be incomplete. Rather than searching for a tight-knit relationship between the functions addressed in the setting manipulation category, take a step back and consider the sorts of system values that an attacker should not be allowed to control.
- Implementation, Architecture and Design: In general, do not allow user-provided or otherwise untrusted data to control sensitive values. The leverage that an attacker gains by controlling these values is not always immediately obvious, but do not underestimate the creativity of the attacker.
CWE-94: Improper Control of Generation of Code ('Code Injection')
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How to prevent it
- Architecture and Design: Refactor your program so that you do not have to dynamically generate code.
- Architecture and Design: Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
- Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Implementation: For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-3x84-qq85-fj65 OpenClaw: Browser CDP discovery could accept blocked WebSocket URLs | High | Also affects openclaw |
| GHSA-9c3v-684m-579c OpenClaw MCP SSE redirects could forward Authorization headers | Medium | Also affects openclaw |
| GHSA-f397-5vjw-v2c2 OpenClaw: Shell inline-command parsing could miss an allowlist check | High | Also affects openclaw |
| GHSA-rx78-29qr-5hq8 OpenClaw: Workspace-derived service PATH could influence trash command selection | High | Also affects openclaw |
| GHSA-ccwh-wwpp-6wg5 OpenClaw: Host environment sanitizer missed two Node.js control variables | High | Also affects openclaw |
| GHSA-985f-72mj-8gf7 OpenClaw: Tool group policy callers could accept unvalidated group IDs | Medium | Also affects openclaw |
| GHSA-9v8j-9c9g-w66c OpenClaw: Bootstrap token replay could widen pending pairing scopes | Medium | Also affects openclaw |
| GHSA-c226-q6fx-6j6c OpenClaw: macOS Swift exec allowlist missed combined POSIX inline flags | Medium | Also affects openclaw |
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