CVE-2026-109438

3proxy from 0.9.7 through 1.0.1, fixed in commit 206c923, contains an uninitialized stack memory disclosure vulnerability that allows unauthenticated attackers to leak stack bytes via the SOCKS4 reply path when the external-NAT option (-Ne) is configured. Attackers can send a client probe that fails the SOCKS version check to trigger a reply containing uninitialized bytes from the sin structure, exposing high bytes of a userspace pointer that weakens ASLR protections.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/3proxy/3proxy/commit/206c923d6cd433bd2e7196375442650c328b8bfa
https://www.vulncheck.com/advisories/3proxy-uninitialized-stack-memory-disclosure-via-socks4

Configurations

No configuration.

History

14 Oct 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-14 16:17

Updated : 2026-10-16 18:25

NVD link : CVE-2026-109438

Mitre link : CVE-2026-109438

CVE.ORG link : CVE-2026-109438

JSON object : View

Products Affected

No product.

CWE

CWE-908

Use of Uninitialized Resource

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