EUVD-2026-21136
GHSA-8f9r-gr6r-x63q
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:N/UI:N/VC:N/VI:N/VA:L/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
Lifecycle Timeline
4Blast Radius
ecosystem impact- 3 npm packages depend on openclaw (3 direct, 0 indirect)
Ecosystem-wide dependent count for version 2026.3.28.
DescriptionCVE.org
OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.
AnalysisAI
OpenClaw before version 2026.3.25 processes JSON webhook request bodies before validating cryptographic signatures, allowing unauthenticated remote attackers to trigger denial of service by submitting malicious webhook payloads that force computationally expensive JSON parsing operations. The vulnerability exploits a logic-ordering defect where signature validation occurs after resource-intensive parsing, enabling attackers to exhaust server resources without valid credentials. No public exploit code has been identified at the time of analysis, though the attack requires only network access and is trivially exploitable.
Technical ContextAI
OpenClaw is a webhook processing system that validates incoming webhook requests via cryptographic signatures (likely HMAC-based given the context). The vulnerability stems from CWE-696 (Incorrect Behavior Order), a class of flaws where security checks are performed in the wrong sequence. The root cause is architectural: the application parses incoming JSON request bodies into memory and processes them (potentially with schema validation, deserialization, or traversal) before checking the webhook signature. An attacker can craft deeply nested JSON structures, extremely large payloads, or computationally expensive JSON documents that consume CPU and memory during parsing. When the signature validation subsequently fails, the already-expended resources are wasted. This is a classic example of order-of-operations vulnerability in authentication frameworks. The affected product is OpenClaw (CPE: cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:*:*:*) in all versions before 2026.3.25.
RemediationAI
Vendor-released patch: OpenClaw 2026.3.25 or later. Users should upgrade immediately via the official release channels. The upstream fix is confirmed in commit 5e8cb22176e9235e224be0bc530699261eb60e53 (https://github.com/openclaw/openclaw/commit/5e8cb22176e9235e224be0bc530699261eb60e53), which reorders webhook processing logic to validate signatures before parsing JSON request bodies. As a temporary mitigation, if upgrade is not immediately feasible, configure network-level rate limiting or firewall rules to restrict webhook endpoint access to known sender IP addresses or implement request size limits to constrain resource exhaustion potential. However, these workarounds do not eliminate the vulnerability and should not substitute for patching.
Auth bypass in OpenClaw voice-call extension before 2026.2.1. EPSS 0.68%. PoC and patch available.
Privilege escalation in OpenClaw (pre-2026.3.28) allows unauthenticated remote attackers to gain administrative access b
OpenClaw versions 2026.2.22 through 2026.2.24 contain a privilege escalation vulnerability that allows authenticated att
An authorization mismatch vulnerability in OpenClaw versions prior to 2026.3.1 allows authenticated users with operator.
OpenClaw versions prior to 2026.1.29 automatically establish WebSocket connections to attacker-controlled gateway URLs e
Path traversal in OpenClaw through version 2026.3.23 enables unauthenticated remote attackers to read arbitrary files in
OpenClaw sandbox browser functionality launches x11vnc for noVNC observer sessions without requiring authentication, all
OpenClaw versions before 2026.2.26 allow authenticated attackers to write arbitrary files outside the workspace director
OpenClaw versions prior to 2026.2.22 contain a shell environment variable injection vulnerability in the system.run func
OpenClaw versions prior to 2026.2.22 contain a resource exhaustion vulnerability where the application fails to consiste
OpenClaw versions prior to 2026.3.1 contain a sandbox escape vulnerability that allows authenticated attackers with low
OpenClaw versions 2026.1.30 and below fail to validate Telegram webhook secret tokens when `channels.telegram.webhookSec
Same weakness CWE-696 – Incorrect Behavior Order
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today