{"cve":"CVE-2026-39418","nvd":{"published":"2026-04-14T01:16:04.353","modified":"2026-10-26T21:10:00.170","status":"Analyzed","description":"MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, sandbox network protection can be bypassed by using socket.sendto() with the MSG_FASTOPEN flag. This allows authenticated user with tool-editing permissions to reach internal services that are explicitly blocked by the sandbox's banned hosts configuration. MaxKB's sandbox uses LD_PRELOAD to hook the connect() function and block connections to banned IPs, but Linux's sendto() with the MSG_FASTOPEN flag can establish TCP connections directly through the kernel without ever calling connect(), completely bypassing the IP validation. Although sendto is listed in the syscall() wrapper, this is ineffective because glibc invokes the kernel syscall directly rather than routing through the hooked syscall() function. This issue has been fixed in version 2.8.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L","score":7.4},"cwes":["CWE-918"],"references":["https://github.com/1Panel-dev/MaxKB/commit/4d06362750b15390437f1d2e4d14ec79baef8559","https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0","https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-w9g4-q3gm-6q6w"],"products":["maxkb:maxkb"],"source":"nvd","synced_at":"2026-10-26T21:38:48.864438205+00:00"},"epss":{"cve":"CVE-2026-39418","score":0.00198,"percentile":0.09538,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}