CVE-2026-40037: OpenClaw `fetchWithSsrFGuard` Replays Unsafe Request Bodies Vulnerability

HIGH
Advisory Identifier: GHSA-qx8j-g322-qj6m
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CWE-345
Published
Advisory Summary

CVE-2026-40037 is a HIGH `fetchwithssrfguard` replays unsafe request bodies vulnerability (CWE-345: Insufficient Verification of Data Authenticity) affecting OpenClaw libraries in the npm ecosystem. The issue involves `fetchwithssrfguard` replays unsafe request bodies across cross-origin redirects. Remediation is available by upgrading affected packages to version 2026.4.8.

CVE-2026-40037 at a Glance

CVE Identifier CVE-2026-40037
GHSA Identifier GHSA-qx8j-g322-qj6m
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-345: Insufficient Verification of Data Authenticity
Affected Product OpenClaw
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-40037

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: 2026.4.8 
npm install openclaw@2026.4.8
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-2026-40037, 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 2026.4.8), 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-345: Insufficient Verification of Data Authenticity, where the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. 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

## Impact `fetchWithSsrFGuard` replays unsafe request bodies across cross-origin redirects. A guarded fetch could resend unsafe request bodies or headers when following cross-origin redirects. OpenClaw is a user-controlled local assistant. This advisory is scoped to the OpenClaw trust model and does not assume a multi-tenant service boundary. ## Affected Packages / Versions - Package: `openclaw` (npm) - Affected versions: `<2026.3.31` - Patched versions: `2026.4.8` ## Fix The issue was fixed on `main` and is available in the patched npm version listed above. The verified fixed tree is commit `d7c3210cd6f5fdfdc1beff4c9541673e814354d5`. ## Verification The fix was re-checked against `main` before publication, including targeted regression tests for the affected security boundary. ## Credits Thanks @BG0ECV for reporting.

CVE-2026-40037 Affected OpenClaw Versions

1 component(s)
Fixed Versions:
2026.4.8
Product / Package Ecosystem Affected Versions Fixed Version
openclaw
npm/openclaw
npm
< 2026.4.8
2026.4.8

References

GitHub Advisory / Wiki ADVISORY
https://github.com/openclaw/openclaw/security/advisories/GHSA-qx8j-g322-qj6m
NVD — CVE-2026-40037 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40037
Security Fix Commit FIX COMMIT
https://github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5
OpenClaw Source Repository REPOSITORY
https://github.com/openclaw/openclaw
www.vulncheck.com/advisories/openclaw... WEB
https://www.vulncheck.com/advisories/openclaw-unsafe-request-body-replay-via-fetchwithssrfguard-cross-origin-redirects

Frequently Asked Questions

What is CVE-2026-40037?
CVE-2026-40037 is a security vulnerability in OpenClaw involving `fetchWithSsrFGuard` replays unsafe request bodies across cross-origin redirects under CWE-345: Insufficient Verification of Data Authenticity.
Which OpenClaw versions are affected?
Affected versions include releases prior to 2026.4.8 across affected packages: openclaw.
What version fixes CVE-2026-40037?
Upgrading to 2026.4.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is openclaw affected?
Yes, openclaw is affected in releases prior to 2026.4.8. Upgrade your dependency to 2026.4.8 or later.
What CWE is associated with CVE-2026-40037?
CVE-2026-40037 is classified under CWE-345: Insufficient Verification of Data Authenticity (The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.).
How can I check npm dependencies for CVE-2026-40037?
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-qx8j-g322-qj6m",
  "modified" : "2026-04-10T20:24:59Z",
  "published" : "2026-04-09T17:37:08Z",
  "aliases" : [ "CVE-2026-40037" ],
  "summary" : "OpenClaw: `fetchWithSsrFGuard` replays unsafe request bodies across cross-origin redirects",
  "details" : "## Impact\n\n`fetchWithSsrFGuard` replays unsafe request bodies across cross-origin redirects.\n\nA guarded fetch could resend unsafe request bodies or headers when following cross-origin redirects.\n\nOpenClaw is a user-controlled local assistant. This advisory is scoped to the OpenClaw trust model and does not assume a multi-tenant service boundary.\n\n## Affected Packages / Versions\n\n- Package: `openclaw` (npm)\n- Affected versions: `<2026.3.31`\n- Patched versions: `2026.4.8`\n\n## Fix\n\nThe issue was fixed on `main` and is available in the patched npm version listed above. The verified fixed tree is commit `d7c3210cd6f5fdfdc1beff4c9541673e814354d5`.\n\n## Verification\n\nThe fix was re-checked against `main` before publication, including targeted regression tests for the affected security boundary.\n\n## Credits\n\nThanks @BG0ECV for reporting.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "openclaw"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2026.4.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/openclaw/openclaw/security/advisories/GHSA-qx8j-g322-qj6m"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40037"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openclaw/openclaw"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/openclaw-unsafe-request-body-replay-via-fetchwithssrfguard-cross-origin-redirects"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-345" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-09T17:37:08Z",
    "nvd_published_at" : null
  }
}