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Fencer Intel
critical 9.8

CVE-2020-6016 json

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles unreliable segments with negative offsets in function SNP_Receiv…

published 5y ago modified 4mo ago also EUVD-2020-27170

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.0%
EPSS 6.0% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

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.

Patch / fix

  • valvesoftware game_networking_sockets 1.2.0

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Exploit prediction

6.00% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • research.checkpoint.com https://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • n/a Game Networking Sockets

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.