{"id":"CVE-2026-102761","title":"NetX Duo's WebSocket client resets the unmasking cursor to the first `NX_PACKET` each time it advances through a chained packet, while the loop's upper bound belongs to the current packet","summary":"NetX Duo's WebSocket client resets the unmasking cursor to the first `NX_PACKET` each time it advances through a chained packet, while the loop's upper bound belongs to the current packet. With the standard contiguous packet-pool layout,…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-787"],"vendor":"Eclipse Foundation","product":"NetX Duo","affected":["netx_duo >= 6.2.0 <= 6.5.1.202602"],"published":"2026-09-29","updated":"2026-09-29","sourceUpdated":"2026-09-29T18:17:13.450","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-102761","references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-6xgx-v7gw-qjph","label":"emo@eclipse.org"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-09-29T17:41:02.254Z","slug":"CVE-2026-102761","body":"## Overview\n\nNetX Duo's WebSocket client resets the unmasking cursor to the first `NX_PACKET` each time it advances through a chained packet, while the loop's upper bound belongs to the current packet. With the standard contiguous packet-pool layout, a masked server frame split across two packets therefore drives the XOR loop through the first packet's unused payload area and on through the second packet's `NX_PACKET` control block.\n\n\n\nThe four-byte WebSocket masking key controls the bytes written, so the corruption is attacker-chosen rather than incidental.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":51.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}