CVE-2026-121968

Netrek-client-cow through 3.3.3 Out-of-Bounds Read via SP_S_MESSAGE Packets

7.1 High

Netrek-client-cow through 3.3.3 contains an out-of-bounds read vulnerability in short.c handleSMessage() that allows malicious servers to crash clients via an unchecked m_recpt index. Attackers controlling a Netrek server or intercepting the plaintext TCP connection can send SP_S_MESSAGE packets with m_recpt of 36 or more, reading past players[] and shipnos to deny service.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Passive

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.33%Unchanged since Nov 5, 2026

What each source reports

CVE List Score used 7.1

Netrek-client-cow through 3.3.3 Out-of-Bounds Read via SP_S_MESSAGE Packets

Record: CVE-2026-121968
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness: CWE-129
Updated: 2026-11-05

EUVDEUVD-2026-117079 7.1

Record: EUVD-2026-117079
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-05

GitHub AdvisoriesGHSA-353f-5249-rrrg 7.1

Netrek-client-cow through 3.3.3 contains an out-of-bounds read vulnerability in short.c...

Record: GHSA-353f-5249-rrrg
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness: CWE-129
Updated: 2026-11-04

NVD 7.1

Record: CVE-2026-121968
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness: CWE-129
Updated: 2026-11-05

OSV 7.1

Netrek-client-cow through 3.3.3 Out-of-Bounds Read via SP_S_MESSAGE Packets

Record: CVE-2026-121968
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-129
Updated: 2026-11-07

OSVUBUNTU-CVE-2026-121968 7.1

Record: UBUNTU-CVE-2026-121968
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Updated: 2026-11-06

Affected products

quozl netrek-client-cow

Affected packages

Affected packages
Package	Affected	Fixed
`netrek-client-cow` Ubuntu:16.04:LTS	All versions, plus listed versions 3.3.0-3.1	None known
`netrek-client-cow` Ubuntu:18.04:LTS	All versions, plus listed versions 3.3.1-1	None known
`netrek-client-cow` Ubuntu:20.04:LTS	All versions, plus listed versions 3.3.1-4build1	None known
`netrek-client-cow` Ubuntu:22.04:LTS	All versions, plus listed versions 3.3.2-1	None known
`netrek-client-cow` Ubuntu:24.04:LTS	All versions, plus listed versions 3.3.2-13.3.2-1build13.3.2-1build2	None known
`netrek-client-cow` Ubuntu:26.10	All versions, plus listed versions 3.3.2-1build33.3.3-1	None known
`netrek-client-cow` Ubuntu:26.04:LTS	All versions, plus listed versions 3.3.2-1build23.3.2-1build3	None known

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, aliases, references	CVE List, EUVD, NVD, OSV
Nov 5, 2026	references	OSV
Nov 5, 2026	published	EUVD
Nov 4, 2026	published	EUVD, NVD
Nov 4, 2026	aliases, published	EUVD
Nov 4, 2026	first indexed	CVE List, GitHub Advisories

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-121968 is a high vulnerability (CVSS 7.1) in Quozl Netrek-client-cow, published November 4, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 25th percentile. No source names a fixed version.