{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/bytedance/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.1,"id":"CVE-2026-40518"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["path-traversal","file-write","bytedance","deerflow"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eByteDance DeerFlow, a software of unknown purpose, prior to commit 2176b2b, is vulnerable to path traversal and arbitrary file write. The vulnerability lies within the bootstrap-mode custom-agent creation process, specifically due to insufficient validation of the agent name. This flaw allows attackers to bypass intended directory restrictions and write files to arbitrary locations on the system, provided they have the necessary filesystem permissions. The vulnerability was reported on April 17, 2026 and has been assigned CVE-2026-40518. Exploitation of this vulnerability could lead to privilege escalation and system compromise. Defenders should prioritize patching or mitigating this vulnerability to prevent unauthorized file modifications.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker gains low-privileged access to the DeerFlow application.\u003c/li\u003e\n\u003cli\u003eAttacker initiates the creation of a custom agent in bootstrap mode.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious agent name containing path traversal sequences (e.g., \u0026ldquo;../\u0026rdquo;, absolute paths).\u003c/li\u003e\n\u003cli\u003eThe DeerFlow application fails to properly validate the agent name.\u003c/li\u003e\n\u003cli\u003eThe application uses the attacker-supplied agent name to create directories.\u003c/li\u003e\n\u003cli\u003eThe path traversal in the agent name allows the application to create directories outside the intended custom-agent directory.\u003c/li\u003e\n\u003cli\u003eThe attacker uploads files as part of the custom agent creation.\u003c/li\u003e\n\u003cli\u003eThe application writes these files to the attacker-controlled location, resulting in arbitrary file write.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability allows attackers to write arbitrary files to the file system, potentially overwriting system files or planting malicious executables. This could lead to privilege escalation, arbitrary code execution, and complete system compromise. While the number of affected installations is unknown, any system running a vulnerable version of ByteDance DeerFlow is susceptible to this attack. The severity is compounded by the ease of exploitation, requiring only low-privileged access.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the patch or upgrade to a version of ByteDance DeerFlow that includes commit 2176b2b to remediate the vulnerability referenced by CVE-2026-40518.\u003c/li\u003e\n\u003cli\u003eImplement the Sigma rule \u003ccode\u003eDetect Suspicious DeerFlow Agent Creation\u003c/code\u003e to detect exploitation attempts targeting CVE-2026-40518 by monitoring process creation events.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for unusual activity related to custom agent creation endpoints in DeerFlow to detect potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-17T17:17:09Z","date_published":"2026-04-17T17:17:09Z","id":"/briefs/2026-04-deerflow-path-traversal/","summary":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed, allowing attackers to write files outside the intended custom-agent directory.","title":"ByteDance DeerFlow Path Traversal and Arbitrary File Write Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-deerflow-path-traversal/"}],"language":"en","title":"CraftedSignal Threat Feed — Bytedance","version":"https://jsonfeed.org/version/1.1"}