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

HIGH 7.5CVE-2026-35640 · GHSA-3h52-cx59-c456 · Published 09/04/2026 · updated 17/06/2026

In short

CVE-2026-35640 is a HIGH (CVSS 7.5) vulnerability affecting openclaw (openclaw), openclaw.
Chance of exploitation in the next 30 days (EPSS): 0.44%, higher than 38.0% of all vulnerabilities.
Fix: update to 2026.3.25, 2026.3.28 or later.

Package	Affected versions	Patched versions
openclaw openclaw	`< 2026.3.25`	`2026.3.25`
openclaw npm	`< 2026.3.28`	`2026.3.28`

Description

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

NVD description

OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.

References

openclaw/openclaw security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2026-35640 · ADVISORY
openclaw/openclaw commit 5e8cb22 · WEB
openclaw/openclaw · PACKAGE
vulncheck.com/advisories/openclaw-denial-of-service-via-unauthenticated-webhook-request-parsing · WEB

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Package

Affected versions

Patched versions

openclaw

< 2026.3.25

2026.3.25

openclaw

npm

< 2026.3.28

2026.3.28

Description

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

Verified vulnerable on tag v2026.3.24 and fixed on main by commit 5e8cb22176e9235e224be0bc530699261eb60e53.

Fix Commit(s)

5e8cb22176e9235e224be0bc530699261eb60e53

NVD description

More vulnerabilities in openclaw

See all →