CVE-2026-28478: OpenClaw < 2026.2.13 - Denial of Service via Unbounded Webhook Request Body Buffering

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-05 · updated 2026-06-17
Weakness: CWE-770

Description

OpenClaw versions prior to 2026.2.13 contain a denial of service vulnerability in webhook handlers that buffer request bodies without strict byte or time limits. Remote unauthenticated attackers can send oversized JSON payloads or slow uploads to webhook endpoints causing memory pressure and availability degradation.

Affected products

OpenClaw: before 2026.2.13 — fixed in 2026.2.13

How to fix

Upgrade to a fixed version: OpenClaw 2026.2.13. Check the vendor advisory for mitigations.

References

https://github.com/openclaw/openclaw/commit/3cbcba10cf30c2ffb898f0d8c7dfb929f15f8930
https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cgh
https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-webhook-request-body-buffering

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