{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/multipart/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"id":"CVE-2026-8468"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["plug"],"_cs_severities":["medium"],"_cs_tags":["denial-of-service","multipart","web-application"],"_cs_type":"advisory","_cs_vendors":["Erlang"],"content_html":"\u003cp\u003ePlug, a popular web application library for Elixir, is susceptible to a denial-of-service vulnerability (CVE-2026-8468) within its multipart header parsing functionality. The vulnerability resides in the \u003ccode\u003ePlug.Conn.read_part_headers/2\u003c/code\u003e function, which fails to enforce limits on the size of the accumulated buffer when parsing multipart/form-data requests. This flaw allows an unauthenticated attacker to send specially crafted HTTP requests containing excessively large multipart headers, leading to uncontrolled memory allocation on the server. By repeatedly sending such requests, an attacker can exhaust available memory resources, ultimately causing the server to crash or become unresponsive, resulting in a denial of service. Specifically, versions \u0026gt;= 1.4.0, \u0026lt; 1.15.4, versions \u0026gt;= 1.16.0, \u0026lt; 1.16.3, versions \u0026gt;= 1.17.0, \u0026lt; 1.17.1, versions \u0026gt;= 1.18.0, \u0026lt; 1.18.2 and versions \u0026gt;= 1.19.0, \u0026lt; 1.19.2 are affected.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a Plug-based web application that utilizes \u003ccode\u003ePlug.Parsers\u003c/code\u003e with the \u003ccode\u003e:multipart\u003c/code\u003e parser or calls \u003ccode\u003ePlug.Conn.read_part_headers/2\u003c/code\u003e directly.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request with the \u003ccode\u003eContent-Type\u003c/code\u003e header set to \u003ccode\u003emultipart/form-data\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eWithin the multipart data, the attacker constructs a part header with an excessively large size, exceeding expected limits. The attacker omits a closing boundary to continue the uncontrolled header accumulation.\u003c/li\u003e\n\u003cli\u003eThe attacker sends the crafted HTTP request to the vulnerable endpoint of the Plug application.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003ePlug.Conn.read_part_headers/2\u003c/code\u003e function processes the request and begins accumulating the multipart header data without proper length validation.\u003c/li\u003e\n\u003cli\u003eThe function continuously allocates memory to store the expanding header buffer, consuming available server resources.\u003c/li\u003e\n\u003cli\u003eThe attacker repeats the process by sending multiple malicious requests, accelerating memory exhaustion.\u003c/li\u003e\n\u003cli\u003eEventually, the server runs out of memory, causing the Plug application to crash or become unresponsive, resulting in 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 leads to a denial-of-service condition, rendering the affected Plug-based web application unavailable to legitimate users. The impact could range from temporary service disruptions to prolonged outages, depending on the severity of the memory exhaustion and the system\u0026rsquo;s recovery capabilities. The number of victims depends on the popularity and criticality of the affected applications. There is no evidence of widespread exploitation at this time.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade to Plug version 1.15.4, 1.16.3, 1.17.1, 1.18.2, 1.19.2, or later, which includes the patch for CVE-2026-8468 (see References).\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Suspicious Multipart Form Request\u003c/code\u003e to identify and block requests with abnormally large multipart headers.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for a high volume of \u003ccode\u003emultipart/form-data\u003c/code\u003e requests with unusually large header sizes.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-20T15:36:29Z","date_published":"2026-05-20T15:36:29Z","id":"https://feed.craftedsignal.io/briefs/2026-05-plug-multipart-dos/","summary":"Plug versions 1.4.0 to 1.19.1 are vulnerable to denial-of-service (CVE-2026-8468) due to unbounded buffer accumulation in multipart header parsing, allowing an unauthenticated attacker to exhaust server memory by sending a crafted multipart/form-data request.","title":"Plug Multipart Header Parsing Denial-of-Service Vulnerability (CVE-2026-8468)","url":"https://feed.craftedsignal.io/briefs/2026-05-plug-multipart-dos/"}],"language":"en","title":"CraftedSignal Threat Feed — Multipart","version":"https://jsonfeed.org/version/1.1"}