{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/undici--8.0.0--8.2.0/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["undici \u003e= 7.23.0 \u003c 7.28.0","undici \u003e= 8.0.0 \u003c 8.2.0"],"_cs_severities":["high"],"_cs_tags":["library-vulnerability","cross-origin-request","data-leakage","nodejs"],"_cs_type":"advisory","_cs_vendors":["Node.js"],"content_html":"\u003cp\u003eThe \u003ccode\u003eundici\u003c/code\u003e Node.js HTTP/1.1 client library contains a high-severity vulnerability, identified as CVE-2026-6734, impacting its \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e component. This flaw, introduced in \u003ccode\u003eundici\u003c/code\u003e version 7.23.0 and affecting all versions up to 8.1.0, allows for cross-origin request routing. When an application uses \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e (either directly or via \u003ccode\u003esetGlobalDispatcher\u003c/code\u003e) and makes requests to multiple distinct origins, the library incorrectly reuses a single SOCKS5 connection pool without verifying that the pool's established origin matches the intended destination of subsequent requests. This misrouting can lead to sensitive data exposure, such as credentials, being sent to unintended destinations, and can cause HTTPS requests to be silently downgraded to HTTP, undermining security. This vulnerability is critical for applications that interact with various services through a shared SOCKS5 proxy agent.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn application initializes and configures \u003ccode\u003eundici\u003c/code\u003e to use a \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e for outgoing network requests, either globally via \u003ccode\u003esetGlobalDispatcher\u003c/code\u003e or locally.\u003c/li\u003e\n\u003cli\u003eThe application makes its first request to an \u003ccode\u003eorigin_A\u003c/code\u003e (e.g., \u003ccode\u003emalicious-domain.com\u003c/code\u003e) through the configured \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003eundici\u003c/code\u003e establishes a connection pool to \u003ccode\u003eorigin_A\u003c/code\u003e via the SOCKS5 proxy, associating this pool with the first requested origin.\u003c/li\u003e\n\u003cli\u003eSubsequently, the application attempts to make a request to a legitimate \u003ccode\u003eorigin_B\u003c/code\u003e (e.g., \u003ccode\u003esecure-service.com\u003c/code\u003e) using the \u003cem\u003esame\u003c/em\u003e \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e instance.\u003c/li\u003e\n\u003cli\u003eDue to the vulnerability, \u003ccode\u003eundici\u003c/code\u003e reuses the existing connection pool (which was established for \u003ccode\u003eorigin_A\u003c/code\u003e) for the request to \u003ccode\u003eorigin_B\u003c/code\u003e, without validating the target origin.\u003c/li\u003e\n\u003cli\u003eAs a result, sensitive request data, including credentials, intended for \u003ccode\u003eorigin_B\u003c/code\u003e is misdirected and sent to \u003ccode\u003eorigin_A\u003c/code\u003e through the established SOCKS5 proxy connection.\u003c/li\u003e\n\u003cli\u003eThe application may then receive and trust responses from \u003ccode\u003eorigin_A\u003c/code\u003e, mistakenly believing they originated from \u003ccode\u003eorigin_B\u003c/code\u003e, leading to data corruption or further compromise.\u003c/li\u003e\n\u003cli\u003eFurthermore, if \u003ccode\u003eorigin_A\u003c/code\u003e supports HTTP and the connection was established as such, HTTPS requests intended for \u003ccode\u003eorigin_B\u003c/code\u003e can be silently downgraded to HTTP, compromising encryption and integrity.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe primary impact of this vulnerability is the unintended exposure of sensitive data and potential compromise of application integrity. Applications that utilize \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e and interact with multiple origins are at risk. Credentials and request bodies intended for one origin can be misdirected to another, allowing an attacker to intercept or manipulate data. This can lead to unauthorized access, data breaches, and service disruption. Additionally, the silent downgrade of HTTPS requests to HTTP strips away crucial transport layer security, making communications vulnerable to eavesdropping and tampering. There is no specific victim count or sector information available, but any Node.js application using vulnerable versions of \u003ccode\u003eundici\u003c/code\u003e in the described configuration is affected.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately upgrade \u003ccode\u003enpm/undici\u003c/code\u003e to version \u003ccode\u003ev7.28.0\u003c/code\u003e or \u003ccode\u003ev8.2.0\u003c/code\u003e or later to apply the official patches for CVE-2026-6734.\u003c/li\u003e\n\u003cli\u003eIf immediate upgrade is not possible, implement the recommended workarounds by using a separate \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e instance per origin for \u003ccode\u003eundici\u003c/code\u003e or avoid using \u003ccode\u003eSocks5ProxyAgent\u003c/code\u003e with multiple origins.\u003c/li\u003e\n\u003cli\u003eDeploy the provided Sigma rules to detect anomalous network traffic from \u003ccode\u003enode.exe\u003c/code\u003e processes that might indicate misrouted requests, specifically observing for connections to private IP ranges or unexpected HTTP traffic to external hosts.\u003c/li\u003e\n\u003cli\u003eEnable comprehensive network connection logging for \u003ccode\u003enode.exe\u003c/code\u003e processes on all affected operating systems to improve visibility into potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-06-19T14:27:57Z","date_published":"2026-06-19T14:27:57Z","id":"https://feed.craftedsignal.io/briefs/2026-06-undici-socks5-proxy-vulnerability/","summary":"The undici library, when using `Socks5ProxyAgent`, is vulnerable to cross-origin request routing if a single connection pool is reused across different origins, potentially misdirecting requests and credentials, trusting responses from the wrong origin, and silently downgrading HTTPS requests to HTTP (CVE-2026-6734).","title":"undici Library Vulnerable to Cross-Origin Request Routing via SOCKS5 Proxy Reuse (CVE-2026-6734)","url":"https://feed.craftedsignal.io/briefs/2026-06-undici-socks5-proxy-vulnerability/"}],"language":"en","title":"CraftedSignal Threat Feed - Undici \u003e= 8.0.0 \u003c 8.2.0","version":"https://jsonfeed.org/version/1.1"}