Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach proxied SMS webhook endpoint
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DeliverySend flood of invalid unsigned requests
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ExploitExhaust shared pre-auth rate-limit budget
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ExecutionSigned Twilio callbacks receive HTTP 429
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ImpactTemporary inbound SMS loss
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource consumption limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Requires the OpenClaw SMS/Twilio webhook to be deployed behind a trusted reverse proxy or tunnel such that multiple external clients are collapsed to a single raw proxy socket address (the client identifier used for the pre-signature invalid-request rate limit). In a direct/single-client deployment where clients present distinct socket addresses, the shared-budget exhaustion does not occur. No authentication is needed (PR:N) and no user interaction is required, but exploitation is limited to denial of inbound SMS during the exhausted window - the attacker cannot forge a signed Twilio callback or read any message data, and service self-recovers when the rate-limit window resets. |
| Impact | This is a low-impact availability issue whose CVSS reflects that honestly. The vendor CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L) scores 6.9 but is explicitly confidentiality/integrity-free (VC:N/VI:N) with only Low availability impact (VA:L) - the 6.9 is inflated by CVSS 4.0's network/unauth weighting relative to the real-world consequence, which the description bounds tightly to 'temporary inbound SMS loss' with no data access and no callback forgery. There is no EPSS score, no CISA KEV listing, and no public exploit code identified at time of analysis, so exploitation status is 'no public exploit identified at time of analysis.' Crucially, the flaw is not present in default single-client deployments: it only manifests 'in deployments where the SMS/Twilio webhook sits behind a trusted reverse proxy or tunnel so that multiple external clients share one socket address' - a specific, self-limiting configuration. Net assessment: real but minor. This is a high-CVSS-but-low-real-risk item - a transient, self-healing DoS on an optional SMS integration of a niche open-source agent framework, not an urgent priority. |
| Exploit ScenarioDerived | An OpenClaw operator runs the Twilio SMS webhook behind a shared reverse proxy or tunnel, so all inbound requests present the same socket address. An unauthenticated remote attacker floods the endpoint with invalid (unsigned) requests, exhausting the shared pre-authentication invalid-request rate-limit budget before signature verification runs. Legitimate, correctly-signed Twilio callbacks then receive HTTP 429 and are dropped, silencing inbound SMS until the shared window resets. No public exploit code is known. |
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Alert meAnalysisAIv1 – Sep 26, 2026
Denial of inbound SMS message ingestion in the OpenClaw npm package (versions 2026.6.6 up to but not including 2026.8.1) allows an unauthenticated remote sender to exhaust the shared pre-authentication rate-limit budget on the Twilio SMS webhook with invalid requests, so that legitimate, correctly signed Twilio callbacks are subsequently answered with HTTP 429 and inbound SMS is temporarily dropped. The issue only manifests in deployments where the SMS/Twilio webhook sits behind a trusted reverse proxy or tunnel such that many external clients collapse to a single raw proxy socket address, because OpenClaw keys that pre-signature limit on the raw socket address rather than a verified or forwarded client identity. Impact is availability only: the attacker cannot forge a signed Twilio callback, cannot read message data, and service recovers automatically once the rate-limit window resets. No public exploit identified at time of analysis, and the vendor-released patch is version 2026.8.1.
RemediationAI
Upgrade the 'openclaw' npm package to version 2026.8.1 or later, the vendor-released patch in which the SMS webhook invalid-request rate limiting is corrected; see the GitHub security advisory at https://github.com/openclaw/openclaw/security/advisories/GHSA-xw48-j584-r73h and the VulnCheck advisory at https://www.vulncheck.com/advisories/openclaw-before-2026.8.1-sms-webhook-rate-limit-bypass. Where immediate upgrade is not possible, the most effective compensating control is to stop collapsing client identities on the webhook path: terminate the SMS/Twilio webhook directly rather than through a shared proxy or tunnel, or configure the front end so that the address OpenClaw observes is not a single shared socket address - this restores per-client budgeting but requires deployment changes and does not fix the pre-signature ordering flaw itself. Alternatively, raise or disable the pre-authentication invalid-request limit in front of the webhook (or front the endpoint with an upstream edge rate limiter keyed on the real forwarded client IP), accepting the trade-off that pre-auth abuse traffic is then less constrained and the upstream limiter must itself be correctly configured to trust forwarded headers. Also consider monitoring for elevated HTTP 429 responses on the Twilio callback route as a detection signal for budget-exhaustion attempts. Because exploitation requires no authentication (PR:N) and no user interaction (UI:N), the exposure persists for any reliant deployment until the 2026.8.1 fix is applied.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
OpenClaw is a Node.js application distributed via the npm package 'openclaw' (CPE cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:*:*:*, tracked by EUVD-2026-87480), and the vulnerable component is its inbound SMS webhook integration for Twilio. The root cause class is CWE-400 (Uncontrolled Resource Consumption): the application enforces its invalid-request rate limit before performing Twilio signature verification, so unauthenticated, unsigned garbage requests consume the same budget that legitimate signed callbacks need. Compounding this, the rate-limit key is derived from the raw proxy socket address instead of a validated client identifier, which is a classic proxy-deployment pitfall - when a trusted reverse proxy or tunnel fronts the webhook, every external client appears to originate from the same address, turning a per-client quota into a single global quota. Because the limit is applied pre-authentication, the attacker needs no Twilio credentials and no valid signature; conversely, because the check is pre-authentication, the attacker gains no ability to inject forged callbacks or access message contents, which is why the CVSS:4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N) and the independent CVSS:3.1 assessment (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) both score this as a low-impact availability defect rather than a confidentiality or integrity compromise.
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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
Remote unauthenticated flooding (AV:N/AC:L/PR:N/UI:N) yields only transient, partial availability loss on the SMS integration (A:L); no confidentiality or integrity impact.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
1DescriptionCVE.org
OpenClaw (npm package 'openclaw') versions >= 2026.6.6 and < 2026.8.1 apply the SMS webhook invalid-request rate limit before Twilio signature verification and identify clients only by the raw proxy socket address. In deployments where the SMS/Twilio webhook sits behind a trusted reverse proxy or tunnel so that multiple external clients share one socket address, an unauthenticated remote sender can exhaust the shared pre-authentication rate-limit budget with invalid requests, causing subsequent correctly signed Twilio callbacks to receive HTTP 429 responses. The result is temporary inbound SMS loss while the shared window remains exhausted; the attacker cannot forge a callback or access message data. Fixed in 2026.8.1.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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
Directory-context bypass in OpenClaw before 2026.8.1 allows authenticated attackers with user interaction to reuse an 'a
Unauthenticated access to the noVNC observer interface in OpenClaw's Docker sandbox browser allows anyone who can reach
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
EUVD-2026-87480
GHSA-r2rq-3p63-8cqm
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB