CVE-2020-6016: Valvesoftware Game Networking Sockets

Critical severity, CVSS 9.8. EPSS: 6% chance of exploitation in the next 30 days.

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles unreliable segments with negative offsets in function SNP_ReceiveUnreliableSegment(), leading to a Heap-Based Buffer Underflow and a free() of memory not from the heap, resulting in a memory corruption and probably even a remote code execution.

Affected products

• Valvesoftware Game Networking Sockets: before 1.2.0 (fixed in 1.2.0)

Published 2020-11-18. Last modified 2026-06-17.