{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/deepstream-server/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.9,"id":"CVE-2026-49252"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["deepstream server","npm/@deepstream/server"],"_cs_severities":["critical"],"_cs_tags":["prototype-pollution","vulnerability","privilege-escalation","deepstream","npm"],"_cs_type":"advisory","_cs_vendors":["deepstreamIO"],"content_html":"\u003cp\u003eThe deepstream server, specifically versions up to 10.0.4, is affected by a critical prototype pollution vulnerability, identified as CVE-2026-49252. This flaw allows an authenticated attacker, who possesses write permissions to any record within the deepstream system, to potentially escalate their privileges. Prototype pollution can lead to the modification of fundamental JavaScript object prototypes, which can then be leveraged to alter application logic, bypass security controls, or achieve arbitrary code execution, ultimately compromising server integrity. The vulnerability is present in the \u003ccode\u003enpm/@deepstream/server\u003c/code\u003e package. Developers are strongly urged to upgrade to version 10.0.5 or implement the recommended workaround to mitigate this risk, ensuring the security of their deepstream deployments.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003e\u003cstrong\u003eInitial Access \u0026amp; Authentication\u003c/strong\u003e: An attacker obtains valid credentials for an authenticated user account with write permissions to at least one data record within the deepstream server.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eIdentify Writeable Record\u003c/strong\u003e: The attacker identifies a specific data record within the deepstream server that their authenticated user account has permissions to modify.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eCraft Malicious Payload\u003c/strong\u003e: The attacker constructs a data modification message, such as a \u003ccode\u003eSET\u003c/code\u003e operation, targeting the identified record. This message includes a data path or key containing the string \u003ccode\u003e__proto__\u003c/code\u003e, \u003ccode\u003econstructor\u003c/code\u003e, or \u003ccode\u003eprototype\u003c/code\u003e (e.g., \u003ccode\u003e{\u0026quot;someField.__proto__.isAdmin\u0026quot;: true}\u003c/code\u003e or \u003ccode\u003e{\u0026quot;data\u0026quot;: {\u0026quot;__proto__\u0026quot;: {\u0026quot;isAdmin\u0026quot;: true}}}\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eSend Malicious Message\u003c/strong\u003e: The crafted message is sent to the vulnerable deepstream server through its API or client interface. This might occur via an HTTP request body or, in some cases, via URI components.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003ePrototype Pollution Trigger\u003c/strong\u003e: The deepstream server processes the incoming message. Due to the prototype pollution vulnerability (CVE-2026-49252), the server improperly handles the special prototype path component within the message, leading to the modification of the \u003ccode\u003eObject.prototype\u003c/code\u003e or a similar base object prototype in the server's JavaScript environment.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003ePrivilege Escalation\u003c/strong\u003e: The attacker leverages the polluted prototype to inject or modify properties (e.g., \u003ccode\u003eisAdmin\u003c/code\u003e flags, internal configuration settings, or references to executable functions) that are subsequently used by other parts of the server application.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eImpact Fulfillment\u003c/strong\u003e: Through this manipulation, the attacker successfully elevates their own privileges within the deepstream server, potentially gaining administrative control, accessing sensitive data, or executing arbitrary commands within the server's context.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe successful exploitation of CVE-2026-49252 can lead to severe consequences, primarily privilege escalation. Any authenticated user with write permissions to any record can elevate their privileges, potentially gaining administrative access over the deepstream server. This could result in complete compromise of the data managed by deepstream, unauthorized access to sensitive information, arbitrary code execution on the server, and disruption of services. While no specific victim counts are provided, all deepstream server instances running vulnerable versions (up to 10.0.4) are at risk, necessitating immediate action to prevent broad compromise.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade the \u003ccode\u003e@deepstream/server\u003c/code\u003e package to version \u003ccode\u003e10.0.5\u003c/code\u003e immediately to patch CVE-2026-49252.\u003c/li\u003e\n\u003cli\u003eImplement the recommended workaround by filtering all incoming messages containing the strings \u003ccode\u003e__proto__\u003c/code\u003e, \u003ccode\u003econstructor\u003c/code\u003e, or \u003ccode\u003eprototype\u003c/code\u003e in their path before they reach the deepstream server's message pipeline.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule below to your SIEM to detect attempts to exploit this vulnerability against webserver logs by monitoring URI paths and query parameters.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-03T10:25:24Z","date_published":"2026-07-03T10:25:24Z","id":"https://feed.craftedsignal.io/briefs/2026-07-deepstream-prototype-pollution/","summary":"Deepstream server versions up to and including 10.0.4 are vulnerable to prototype pollution (CVE-2026-49252), a critical flaw allowing any authenticated user with write permissions to any record to potentially escalate their privileges; the vulnerability is patched in version 10.0.5.","title":"Deepstream Server Prototype Pollution (CVE-2026-49252) Allows Privilege Escalation","url":"https://feed.craftedsignal.io/briefs/2026-07-deepstream-prototype-pollution/"}],"language":"en","title":"CraftedSignal Threat Feed - Deepstream Server","version":"https://jsonfeed.org/version/1.1"}