CVE-2026-109438

3proxy 0.9.7 - 1.0.1 Uninitialized Stack Memory Disclosure via SOCKS4

Published Oct 14, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:3proxy:3proxy:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared 3proxy
3proxy 3proxy
Vendors & Products 3proxy
3proxy 3proxy
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title 3proxy 0.9.7 - 1.0.1 Uninitialized Stack Memory Disclosure via SOCKS4
Weaknesses CWE-908
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 27, 2026, 1:30 AM
Reserved
Oct 12, 2026, 3:52 PM
Status
Deferred
Published
Oct 14, 2026, 4:17 PM
Modified
Oct 16, 2026, 6:25 PM