{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-41405/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-41405"}],"_cs_exploited":false,"_cs_products":["OpenClaw"],"_cs_severities":["medium"],"_cs_tags":["resource-exhaustion","webhook","cve-2026-41405"],"_cs_type":"advisory","_cs_vendors":["OpenClaw"],"content_html":"\u003cp\u003eOpenClaw before version 2026.3.31 is vulnerable to a resource exhaustion attack due to improper handling of MS Teams webhook requests. The application parses the request body before validating the JWT, which allows unauthenticated attackers to send malicious payloads. By sending specially crafted Teams webhook payloads, attackers can bypass authentication checks and exhaust server resources. This vulnerability, identified as CVE-2026-41405, can lead to denial of service and impacts systems where OpenClaw is used to process MS Teams webhooks. Successful exploitation can severely degrade or halt OpenClaw\u0026rsquo;s functionality.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn unauthenticated attacker identifies an OpenClaw instance processing MS Teams webhooks.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious MS Teams webhook payload designed to consume excessive resources during parsing.\u003c/li\u003e\n\u003cli\u003eThe attacker sends the malicious webhook payload to the OpenClaw endpoint.\u003c/li\u003e\n\u003cli\u003eOpenClaw receives the webhook request and begins parsing the request body \u003cem\u003ebefore\u003c/em\u003e JWT validation.\u003c/li\u003e\n\u003cli\u003eThe malicious payload triggers excessive resource consumption (CPU, memory) during the parsing stage.\u003c/li\u003e\n\u003cli\u003eThe parsing process exhausts available server resources.\u003c/li\u003e\n\u003cli\u003eOpenClaw becomes unresponsive or crashes due to resource exhaustion.\u003c/li\u003e\n\u003cli\u003eLegitimate MS Teams webhook requests are no longer processed, leading to a denial of service.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability can lead to a denial-of-service condition, rendering OpenClaw unresponsive. This can disrupt any services relying on OpenClaw for MS Teams webhook processing. While the precise number of affected organizations is unknown, any organization using a vulnerable version of OpenClaw is at risk. The impact includes potential loss of data, interrupted workflows, and reputational damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade OpenClaw to version 2026.3.31 or later to patch CVE-2026-41405.\u003c/li\u003e\n\u003cli\u003eImplement rate limiting on the MS Teams webhook endpoint to mitigate resource exhaustion, even after patching.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs (category \u003ccode\u003ewebserver\u003c/code\u003e, product \u003ccode\u003elinux\u003c/code\u003e) for unusual traffic patterns and large request sizes to the MS Teams webhook endpoint.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect High Number of Requests to Teams Webhook\u003c/code\u003e to identify potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-29T12:00:00Z","date_published":"2026-04-29T12:00:00Z","id":"/briefs/2026-04-openclaw-resource-exhaustion/","summary":"OpenClaw before 2026.3.31 parses MS Teams webhook request bodies before performing JWT validation, allowing unauthenticated attackers to exhaust server resources by sending malicious Teams webhook payloads.","title":"OpenClaw MS Teams Webhook Resource Exhaustion Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-openclaw-resource-exhaustion/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-41405","version":"https://jsonfeed.org/version/1.1"}