Which versions of OpenClaw are affected by EUVD-2026-27253?

OpenClaw versions 2026.2.22 through 2026.4.11 contain a high-severity authentication bypass vulnerability allowing low-privileged users to execute arbitrary code by manipulating shell environment…. A patch is available.

How to fix or mitigate EUVD-2026-27253?

Within 24 hours: Identify all systems running OpenClaw versions 2026.2.22-2026.4.11 via asset inventory and isolate any internet-facing instances. Within 7 days: Test and deploy vendor patch to OpenClaw 2026.4.12 in non-production environment, then execute staged production rollout. Within 30 days: Complete patch deployment across all affected instances and validate successful remediation via version audit.

OpenClaw EUVD-2026-27253

Q: What is the CVSS score of EUVD-2026-27253?

EUVD-2026-27253 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.1%.

| CVE-2026-42435 HIGH

Incomplete List of Disallowed Inputs (CWE-184)

2026-05-05 VulnCheck

Authentication Bypass Openclaw

8.7

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

8.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

May 05, 2026 - 12:53 vuln.today

v2 (cvss_changed)

Re-analysis Queued

May 05, 2026 - 12:37 vuln.today

cvss_changed

CVSS changed

May 05, 2026 - 12:37 NVD

8.8 (HIGH) 8.7 (HIGH)

Source Code Evidence Fetched

May 05, 2026 - 12:15 vuln.today

Analysis Generated

May 05, 2026 - 12:15 vuln.today

DescriptionCVE.org

OpenClaw versions from 2026.2.22 before 2026.4.12 contain an insufficient shell-wrapper detection vulnerability allowing attackers to inject environment variable assignments at the argv level. Attackers can bypass exec preflight handling to manipulate high-risk shell variables like SHELLOPTS and PS4, affecting execution semantics and security controls.

AnalysisAI

Remote attackers with low-privilege authentication can inject environment variable assignments into OpenClaw 2026.2.22 through 2026.4.11 to bypass shell wrapper detection mechanisms. By manipulating critical shell variables like SHELLOPTS and PS4 at the argv level, attackers achieve high-impact code execution that circumvents security controls. Vendor-released patch available in version 2026.4.12. No active exploitation confirmed (not in CISA KEV), but VulnCheck disclosed this vulnerability with specific technical details and a GitHub commit fix.

Technical ContextAI

This vulnerability exploits insufficient input validation in OpenClaw's shell wrapper detection logic (CWE-184: Incomplete List of Disallowed Inputs). The application fails to properly sanitize command-line arguments (argv) before execution, allowing injection of environment variable assignments. Critical shell variables like SHELLOPTS (controls shell options including debug tracing) and PS4 (defines the prompt for execution trace) can be manipulated to alter execution flow and disable security mechanisms. The CPE identifier (cpe:2.3:a:openclaw:openclaw) indicates this is a core vulnerability in the OpenClaw application framework itself, affecting how it interfaces with shell environments during command execution or subprocess spawning.

RemediationAI

Upgrade to OpenClaw version 2026.4.12 or later, which contains the fix implemented in commit 8f8492d172f4c5b4fd7dd9a47855ed620c8770ab (https://github.com/openclaw/openclaw/commit/8f8492d172f4c5b4fd7dd9a47855ed620c8770ab). If immediate patching is not feasible, implement strict input validation on all user-controllable data passed to shell execution contexts, specifically blocking argv entries containing '=' characters that could represent environment variable assignments. Alternatively, restrict authenticated user privileges to minimize exposure, though this reduces functionality and does not eliminate the vulnerability. Review audit logs for suspicious SHELLOPTS or PS4 variable usage patterns, particularly trace mode activation or unexpected shell option modifications.