CVE-2026-28478: Openclaw Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-q447-rj3r-2cgh
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CVSS 7.5
CWE-400
Published
Advisory Summary

CVE-2026-28478 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Openclaw libraries in the npm ecosystem. The issue involves openclaw affected by denial of service via unbounded webhook request body buffering. Remediation is available by upgrading affected packages to version 2026.2.13.

CVE-2026-28478 at a Glance

CVE Identifier CVE-2026-28478
GHSA Identifier GHSA-q447-rj3r-2cgh
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Openclaw
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-28478

To remediate this vulnerability, upgrade all affected Openclaw dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

openclaw fixed: 2026.2.13 
npm install openclaw@2026.2.13
clawdbot fixed: Latest secure release 
npm install clawdbot@Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls openclaw

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-28478, inspect your project dependencies using npm:

npm ls openclaw

Analyze the terminal output to locate any version of Openclaw in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2026.2.13), your application is affected.

Note: The npm ls openclaw command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Openclaw, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary Multiple webhook handlers accepted and buffered request bodies without a strict unified byte/time limit. A remote unauthenticated attacker could send oversized payloads and cause memory pressure, degrading availability. ### Details Affected packages: - `openclaw` (npm): `<2026.2.12` - `clawdbot` (npm): `<=2026.1.24-3` Root cause: - Webhook code paths buffered request payloads without consistent `maxBytes` + `timeoutMs` enforcement. - Some SDK-backed handlers parse request bodies internally and needed stream-level guards. Attack shape: - Send very large JSON payloads or slow/incomplete uploads to webhook endpoints. - Observe elevated memory usage and request handler pressure. ### Impact Remote unauthenticated availability impact (DoS) via request body amplification/memory pressure. ### Patch details (implemented) - Added shared bounded request-body helper in `src/infra/http-body.ts`. - Exported helper in `src/plugin-sdk/index.ts` for extension reuse. - Migrated webhook body readers to shared helper for: - LINE - Nextcloud Talk - Google Chat - Zalo - BlueBubbles - Nostr profile HTTP - Voice-call - Gateway hooks - Added stream guards for SDK handlers that parse request bodies internally: - Slack - Telegram - Feishu - Added explicit Express JSON body limit handling for MS Teams webhook path. - Standardized failure responses: - `413 Payload Too Large` - `408 Request Timeout` ### Tests - Added regression tests: - `src/infra/http-body.test.ts` - `src/line/monitor.read-body.test.ts` - `extensions/nextcloud-talk/src/monitor.read-body.test.ts` - Focused webhook/security test suite passes for patched paths. ### Remediation Upgrade to the first release containing this patch. ## Credits Thanks @vincentkoc for reporting.

CVE-2026-28478 Affected Openclaw Versions

2 component(s)
Fixed Versions:
2026.2.13
Product / Package Ecosystem Affected Versions Fixed Version
openclaw
npm/openclaw
npm
< 2026.2.13
2026.2.13
clawdbot
npm/clawdbot
npm
≤ 2026.1.24-3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cgh
Openclaw Source Repository REPOSITORY
https://github.com/openclaw/openclaw

Frequently Asked Questions

What is CVE-2026-28478?
CVE-2026-28478 is a security vulnerability in Openclaw involving OpenClaw affected by denial of service via unbounded webhook request body buffering under CWE-400: Uncontrolled Resource Consumption.
Which Openclaw versions are affected?
Affected versions include releases prior to 2026.2.13 across affected packages: openclaw, clawdbot.
What version fixes CVE-2026-28478?
Upgrading to 2026.2.13 (or the latest patched release for your respective branch) resolves the vulnerability.
Is openclaw affected?
Yes, openclaw is affected in releases prior to 2026.2.13. Upgrade your dependency to 2026.2.13 or later.
Is clawdbot affected?
Yes, clawdbot is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-28478?
CVE-2026-28478 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-28478?
CVE-2026-28478 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check npm dependencies for CVE-2026-28478?
Run the dependency tree command: 'npm ls openclaw'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q447-rj3r-2cgh",
  "modified" : "2026-03-05T21:53:39Z",
  "published" : "2026-02-18T00:53:07Z",
  "aliases" : [ "CVE-2026-28478" ],
  "summary" : "OpenClaw affected by denial of service via unbounded webhook request body buffering",
  "details" : "### Summary\nMultiple webhook handlers accepted and buffered request bodies without a strict unified byte/time limit. A remote unauthenticated attacker could send oversized payloads and cause memory pressure, degrading availability.\n\n### Details\nAffected packages:\n- `openclaw` (npm): `<2026.2.12`\n- `clawdbot` (npm): `<=2026.1.24-3`\n\nRoot cause:\n- Webhook code paths buffered request payloads without consistent `maxBytes` + `timeoutMs` enforcement.\n- Some SDK-backed handlers parse request bodies internally and needed stream-level guards.\n\nAttack shape:\n- Send very large JSON payloads or slow/incomplete uploads to webhook endpoints.\n- Observe elevated memory usage and request handler pressure.\n\n### Impact\nRemote unauthenticated availability impact (DoS) via request body amplification/memory pressure.\n\n### Patch details (implemented)\n- Added shared bounded request-body helper in `src/infra/http-body.ts`.\n- Exported helper in `src/plugin-sdk/index.ts` for extension reuse.\n- Migrated webhook body readers to shared helper for:\n  - LINE\n  - Nextcloud Talk\n  - Google Chat\n  - Zalo\n  - BlueBubbles\n  - Nostr profile HTTP\n  - Voice-call\n  - Gateway hooks\n- Added stream guards for SDK handlers that parse request bodies internally:\n  - Slack\n  - Telegram\n  - Feishu\n- Added explicit Express JSON body limit handling for MS Teams webhook path.\n- Standardized failure responses:\n  - `413 Payload Too Large`\n  - `408 Request Timeout`\n\n### Tests\n- Added regression tests:\n  - `src/infra/http-body.test.ts`\n  - `src/line/monitor.read-body.test.ts`\n  - `extensions/nextcloud-talk/src/monitor.read-body.test.ts`\n- Focused webhook/security test suite passes for patched paths.\n\n### Remediation\nUpgrade to the first release containing this patch.\n\n## Credits\nThanks @vincentkoc for reporting.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "openclaw"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2026.2.13"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "clawdbot"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2026.1.24-3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cgh"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openclaw/openclaw"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-18T00:53:07Z",
    "nvd_published_at" : null
  }
}