CVE-2026-35640: OpenClaw Feishu Webhook Reads And Parses Vulnerability

MODERATE
Advisory Identifier: GHSA-3h52-cx59-c456
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CWE-400
Published
Advisory Summary

CVE-2026-35640 is a MODERATE feishu webhook reads and parses vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting OpenClaw libraries in the npm ecosystem. The issue involves feishu webhook reads and parses unauthenticated request bodies before signature validation. Remediation is available by upgrading affected packages to version 2026.3.28.

CVE-2026-35640 at a Glance

CVE Identifier CVE-2026-35640
GHSA Identifier GHSA-3h52-cx59-c456
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product OpenClaw
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-35640

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: 2026.3.28 
npm install openclaw@2026.3.28
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-2026-35640, 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 2026.3.28), 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 Feishu webhook reads and parses unauthenticated request bodies before signature validation ## Affected Packages / Versions - Package: `openclaw` - Affected versions: `<= 2026.3.24` - First patched version: `2026.3.25` - Latest published npm version at verification time: `2026.3.24` ## Details Feishu webhook handling previously parsed JSON before signature validation, which let unauthenticated callers force full JSON parsing work before rejection. Commit `5e8cb22176e9235e224be0bc530699261eb60e53` reads the raw request body, validates the signature first, and only then parses JSON. Verified vulnerable on tag `v2026.3.24` and fixed on `main` by commit `5e8cb22176e9235e224be0bc530699261eb60e53`. ## Fix Commit(s) - `5e8cb22176e9235e224be0bc530699261eb60e53`

CVE-2026-35640 Affected OpenClaw Versions

1 component(s)
Fixed Versions:
2026.3.28
Product / Package Ecosystem Affected Versions Fixed Version
openclaw
npm/openclaw
npm
< 2026.3.28
2026.3.28

References

GitHub Advisory / Wiki ADVISORY
https://github.com/openclaw/openclaw/security/advisories/GHSA-3h52-cx59-c456
NVD — CVE-2026-35640 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35640
Security Fix Commit FIX COMMIT
https://github.com/openclaw/openclaw/commit/5e8cb22176e9235e224be0bc530699261eb60e53
OpenClaw Source Repository REPOSITORY
https://github.com/openclaw/openclaw
www.vulncheck.com/advisories/openclaw... WEB
https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unauthenticated-webhook-request-parsing

Frequently Asked Questions

What is CVE-2026-35640?
CVE-2026-35640 is a security vulnerability in OpenClaw involving Feishu webhook reads and parses unauthenticated request bodies before signature validation under CWE-400: Uncontrolled Resource Consumption.
Which OpenClaw versions are affected?
Affected versions include releases prior to 2026.3.28 across affected packages: openclaw.
What version fixes CVE-2026-35640?
Upgrading to 2026.3.28 (or the latest patched release for your respective branch) resolves the vulnerability.
Is openclaw affected?
Yes, openclaw is affected in releases prior to 2026.3.28. Upgrade your dependency to 2026.3.28 or later.
What CWE is associated with CVE-2026-35640?
CVE-2026-35640 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-2026-35640?
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-3h52-cx59-c456",
  "modified" : "2026-04-10T20:21:35Z",
  "published" : "2026-03-29T15:48:58Z",
  "aliases" : [ "CVE-2026-35640" ],
  "summary" : "OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation",
  "details" : "## Summary\n\nFeishu webhook reads and parses unauthenticated request bodies before signature validation\n\n## Affected Packages / Versions\n\n- Package: `openclaw`\n- Affected versions: `<= 2026.3.24`\n- First patched version: `2026.3.25`\n- Latest published npm version at verification time: `2026.3.24`\n\n## Details\n\nFeishu webhook handling previously parsed JSON before signature validation, which let unauthenticated callers force full JSON parsing work before rejection. Commit `5e8cb22176e9235e224be0bc530699261eb60e53` reads the raw request body, validates the signature first, and only then parses JSON.\n\nVerified vulnerable on tag `v2026.3.24` and fixed on `main` by commit `5e8cb22176e9235e224be0bc530699261eb60e53`.\n\n## Fix Commit(s)\n\n- `5e8cb22176e9235e224be0bc530699261eb60e53`",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "openclaw"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2026.3.28"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/openclaw/openclaw/security/advisories/GHSA-3h52-cx59-c456"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35640"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openclaw/openclaw/commit/5e8cb22176e9235e224be0bc530699261eb60e53"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openclaw/openclaw"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unauthenticated-webhook-request-parsing"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-29T15:48:58Z",
    "nvd_published_at" : null
  }
}