OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · 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 · score source

EPSS

• CVE-2026-35640: 0.44% estimated exploitation activity in the next 30 days; percentile 37.96 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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

Published by the source

29 Mar 2026, 15:48 UTC

Last modified by the source

10 Apr 2026, 20:42 UTC

Source last checked

26 Oct 2026, 12:48 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3h52-cx59-c456

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-3h52-cx59-c456

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-35640

Advisory: OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation
IDs: CVE-2026-35640, GHSA-3h52-cx59-c456
Record: https://patchnext.com/advisories/cve-2026-35640 (revision 3, source checked 26 Oct 2026, 12:48 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: openclaw 2026.3.28. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm openclaw: affected < 2026.3.28; fixed in 2026.3.28

## Suggested inspection (read-only)
- `npm ls openclaw --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on openclaw.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-3h52-cx59-c456 (OSV record GHSA-3h52-cx59-c456 lists affected ranges: npm openclaw >=0 <2026.3.28 (fixed))
- Verified: https://github.com/advisories/GHSA-3h52-cx59-c456 (GitHub-reviewed advisory GHSA-3h52-cx59-c456 lists affected ranges: npm openclaw >=0 <2026.3.28)

Commands are suggestions: review each one before running it.