{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-6594/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.3,"id":"CVE-2026-6594"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["prototype-pollution","javascript","code-injection","cve-2026-6594"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA prototype pollution vulnerability, identified as CVE-2026-6594, affects brikcss merge versions up to 1.3.0. This vulnerability allows a remote attacker to manipulate the \u003cstrong\u003eproto\u003c/strong\u003e/constructor.prototype/prototype argument, leading to the modification of object prototype attributes. The vendor was notified, but did not respond. Successful exploitation can lead to denial of service, code injection, or other unintended behaviors in applications using the affected library. Prototype pollution vulnerabilities are particularly concerning as they can have widespread effects, potentially impacting multiple parts of an application or even other applications sharing the same JavaScript runtime.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable endpoint in an application using brikcss merge \u0026lt;= 1.3.0.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious payload containing a \u003ccode\u003e__proto__\u003c/code\u003e, \u003ccode\u003econstructor.prototype\u003c/code\u003e, or \u003ccode\u003eprototype\u003c/code\u003e property.\u003c/li\u003e\n\u003cli\u003eThe malicious payload is sent to the vulnerable endpoint, often as part of a JSON object within a POST request.\u003c/li\u003e\n\u003cli\u003eThe brikcss merge function processes the payload without proper sanitization or input validation.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003e__proto__\u003c/code\u003e property is used to modify the prototype of JavaScript objects.\u003c/li\u003e\n\u003cli\u003eThe prototype modification injects malicious properties or methods into all objects inheriting from the modified prototype.\u003c/li\u003e\n\u003cli\u003eThe application executes code that relies on the now-polluted prototype.\u003c/li\u003e\n\u003cli\u003eThis leads to unexpected behavior, such as arbitrary code execution, denial-of-service, or information disclosure.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-6594 can lead to a variety of impacts, including denial of service, arbitrary code execution, and information disclosure. Since the vulnerability allows for modification of object prototypes, the impact can be widespread, affecting multiple parts of an application and potentially other applications. The number of affected applications is currently unknown, but any application using a vulnerable version of brikcss merge is potentially at risk.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade brikcss merge to a patched version or remove the library entirely from your project to remediate CVE-2026-6594.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026ldquo;Detect Prototype Pollution via HTTP Request\u0026rdquo; to detect exploitation attempts targeting web applications that use brikcss merge.\u003c/li\u003e\n\u003cli\u003eImplement input validation and sanitization on all user-supplied data processed by brikcss merge to prevent malicious payloads from being processed.\u003c/li\u003e\n\u003cli\u003eReview and audit code that uses brikcss merge to identify potential vulnerable code paths.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for requests containing \u003ccode\u003e__proto__\u003c/code\u003e, \u003ccode\u003econstructor.prototype\u003c/code\u003e, or \u003ccode\u003eprototype\u003c/code\u003e parameters in the request body as described in the attack chain.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-20T02:16:15Z","date_published":"2026-04-20T02:16:15Z","id":"/briefs/2026-04-brikcss-prototype-pollution/","summary":"A prototype pollution vulnerability (CVE-2026-6594) in brikcss merge up to version 1.3.0 allows remote attackers to modify object prototype attributes by manipulating the __proto__/constructor.prototype/prototype argument.","title":"brikcss merge Prototype Pollution Vulnerability (CVE-2026-6594)","url":"https://feed.craftedsignal.io/briefs/2026-04-brikcss-prototype-pollution/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-6594","version":"https://jsonfeed.org/version/1.1"}