{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/vendors/the-libsoup-project/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-15709"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["libsoup"],"_cs_severities":["low"],"_cs_tags":["denial-of-service","vulnerability","libsoup"],"_cs_type":"advisory","_cs_vendors":["The libsoup project"],"content_html":"\u003cp\u003eA significant remote denial of service vulnerability, identified as CVE-2026-15709, has been disclosed within the \u003ccode\u003elibsoup\u003c/code\u003e library. This vulnerability specifically impacts the \u003ccode\u003elibsoup\u003c/code\u003e implementation of the websocket \u003ccode\u003epermessage-deflate\u003c/code\u003e extension, which is designed to compress websocket messages. The flaw lies in an unbounded decompression mechanism, meaning that when a specially crafted, highly compressed message is received, the \u003ccode\u003elibsoup\u003c/code\u003e library attempts to decompress it without adequate resource limits. This uncontrolled decompression leads to excessive consumption of memory and CPU resources on the server. If successfully exploited, this can render the affected application or even the entire system unresponsive, causing a denial of service and disrupting critical operations. Given \u003ccode\u003elibsoup\u003c/code\u003e's role as a fundamental HTTP client/server library, numerous applications could be at risk.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker identifies a publicly accessible application utilizing the vulnerable \u003ccode\u003elibsoup\u003c/code\u003e library for websocket communication.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes a websocket connection with the target application.\u003c/li\u003e\n\u003cli\u003eDuring the websocket handshake, the attacker negotiates the use of the \u003ccode\u003epermessage-deflate\u003c/code\u003e extension.\u003c/li\u003e\n\u003cli\u003eThe attacker sends specially crafted, highly compressed websocket messages through the established connection.\u003c/li\u003e\n\u003cli\u003eThe vulnerable \u003ccode\u003elibsoup\u003c/code\u003e library on the server attempts to decompress these messages.\u003c/li\u003e\n\u003cli\u003eDue to the unbounded decompression vulnerability (CVE-2026-15709), the decompression process consumes an inordinate amount of server memory and CPU.\u003c/li\u003e\n\u003cli\u003eThe target application's resources are exhausted, causing it to become unresponsive or crash, leading to a denial of service for legitimate users.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful exploitation of CVE-2026-15709 would result in the denial of service for applications or systems relying on the vulnerable \u003ccode\u003elibsoup\u003c/code\u003e library. This can lead to severe operational disruptions, causing downtime for services, loss of productivity, and potential financial impact for organizations. While no specific victim counts or sectors are currently disclosed, any service utilizing the affected \u003ccode\u003elibsoup\u003c/code\u003e version that handles websocket connections with \u003ccode\u003epermessage-deflate\u003c/code\u003e is potentially vulnerable to resource exhaustion and service unavailability.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-15709 on all systems using the \u003ccode\u003elibsoup\u003c/code\u003e library immediately to mitigate the remote denial of service vulnerability.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-17T07:09:20Z","date_published":"2026-07-17T07:09:20Z","id":"https://feed.craftedsignal.io/briefs/2026-07-libsoup-websocket-dos/","summary":"A remote denial of service vulnerability, CVE-2026-15709, exists in the libsoup library's websocket permessage-deflate extension, allowing an attacker to trigger a denial of service through unbounded decompression.","title":"libsoup Websocket Unbounded Decompression Denial of Service Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-07-libsoup-websocket-dos/"}],"language":"en","title":"CraftedSignal Threat Feed - The Libsoup Project","version":"https://jsonfeed.org/version/1.1"}