GHSA-Q447-RJ3R-2CGH

Vulnerability from github – Published: 2026-02-18 00:53 – Updated: 2026-03-05 21:53
VLAI
Summary
OpenClaw affected by denial of service via unbounded webhook request body buffering
Details

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.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "openclaw"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2026.2.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "clawdbot"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2026.1.24-3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-28478"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-18T00:53:07Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\nMultiple 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.\n\n### Details\nAffected packages:\n- `openclaw` (npm): `\u003c2026.2.12`\n- `clawdbot` (npm): `\u003c=2026.1.24-3`\n\nRoot cause:\n- Webhook code paths buffered request payloads without consistent `maxBytes` + `timeoutMs` enforcement.\n- Some SDK-backed handlers parse request bodies internally and needed stream-level guards.\n\nAttack shape:\n- Send very large JSON payloads or slow/incomplete uploads to webhook endpoints.\n- Observe elevated memory usage and request handler pressure.\n\n### Impact\nRemote unauthenticated availability impact (DoS) via request body amplification/memory pressure.\n\n### Patch details (implemented)\n- Added shared bounded request-body helper in `src/infra/http-body.ts`.\n- Exported helper in `src/plugin-sdk/index.ts` for extension reuse.\n- Migrated webhook body readers to shared helper for:\n  - LINE\n  - Nextcloud Talk\n  - Google Chat\n  - Zalo\n  - BlueBubbles\n  - Nostr profile HTTP\n  - Voice-call\n  - Gateway hooks\n- Added stream guards for SDK handlers that parse request bodies internally:\n  - Slack\n  - Telegram\n  - Feishu\n- Added explicit Express JSON body limit handling for MS Teams webhook path.\n- Standardized failure responses:\n  - `413 Payload Too Large`\n  - `408 Request Timeout`\n\n### Tests\n- Added regression tests:\n  - `src/infra/http-body.test.ts`\n  - `src/line/monitor.read-body.test.ts`\n  - `extensions/nextcloud-talk/src/monitor.read-body.test.ts`\n- Focused webhook/security test suite passes for patched paths.\n\n### Remediation\nUpgrade to the first release containing this patch.\n\n## Credits\nThanks @vincentkoc for reporting.",
  "id": "GHSA-q447-rj3r-2cgh",
  "modified": "2026-03-05T21:53:39Z",
  "published": "2026-02-18T00:53:07Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-q447-rj3r-2cgh"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/openclaw/openclaw"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenClaw affected by denial of service via unbounded webhook request body buffering"
}



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