CVE-2026-102761: eclipse foundation netx duo Out-of-bounds Write

Vulnerability summary

CVE-2026-102761 is a critical (CVSS 9.3) Out-of-bounds Write vulnerability in eclipse foundation netx duo. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.7% of scored vulnerabilities.

Timeline

1. 29-09-2026
   PublishedVulnerability first disclosed.
2. 30-09-2026
   Last modifiedVulnerability information updated.

Description

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, 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. The four-byte WebSocket masking key controls the bytes written, so the corruption is attacker-chosen rather than incidental.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.