CVE-2026-28478
highpriority · track · 0EPSS 0.005 · 40 %ileDEEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (7)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0424OpenClaw: Mehrere SchwachstellenDeutsch2026-02-15csaf · cert_bundDE
Ein Angreifer kann diese Schwachstellen in OpenClaw ausnutzen, um beliebigen Programmcode auszuführen, sich erhöhte Berechtigungen zu verschaffen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren, einen Denial-of-Service-Zustand herbeizuführen, vertrauliche Informationen offenzulegen oder andere, nicht näher bezeichnete Angriffe durchzuführen.
- GHSA-q447-rj3r-2cghOpenClaw affected by denial of service via unbounded webhook request body buffering2026-02-18ghsa · osvUS
### Summary Multiple webhook handlers accepted and buffered request bodies without a strict unified byte/time limit. A remote unauthenticated attacker could send oversized payloads and cause memory pressure, degrading availability. ### Details Affected packages: - `openclaw` (npm): `<2026.2.12` - `clawdbot` (npm): `<=2026.1.24-3` Root cause: - Webhook code paths buffered request payloads without consistent `maxBytes` + `timeoutMs` enforcement. - Some SDK-backed handlers parse request bodies internally and needed stream-level guards. Attack shape: - Send very large JSON payloads or slow/incomplete uploads to webhook endpoints. - Observe elevated memory usage and request handler pressure. ### Impact Remote unauthenticated availability impact (DoS) via request body amplification/memory pressure. ### Patch details (implemented) - Added shared bounded request-body helper in `src/infra/http-body.ts`. - Exported helper in `src/plugin-sdk/index.ts` for extension reuse. - Migrated webhook body readers to shared helper for: - LINE - Nextcloud Talk - Google Chat - Zalo - BlueBubbles - Nostr profile HTTP - Voice-call - Gateway hooks - Added stream guards for SDK handlers that parse request bodies internally: - Slack - Telegram - Feishu - Added explicit Express JSON body limit handling for MS Teams webhook path. - Standardized failure responses: - `413 Payload Too Large` - `408 Request Timeout` ### Tests - Added regression tests: - `src/infra/http-body.test.ts` - `src/line/monitor.read-body.test.ts` - `extensions/nextcloud-talk/src/monitor.read-body.test.ts` - Focused webhook/security test suite passes for patched paths. ### Remediation Upgrade to the first release containing this patch. ## Credits Thanks @vincentkoc for reporting.
also known as (4)
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sources
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references (10)
External citations — patches, advisories, analysis.
- https://github.com/openclaw/openclaw/commit/3cbcba10cf30c2ffb898f0d8c7dfb929f15f8930cnnvd
- https://github.com/openclaw/openclaw/releasesPatchcnnvd
- https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cghcnnvd
- https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-webhook-request-body-bufferingcnnvd
- https://github.com/openclaw/openclaw/commit/3cbcba10cf30c2ffb898f0d8c7dfb929f15f8930enisa_euvd
- https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cghenisa_euvd
- https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-webhook-request-body-bufferingenisa_euvd
- https://github.com/openclaw/openclaw/commit/3cbcba10cf30c2ffb898f0d8c7dfb929f15f8930Patchnvd
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