All vulnerabilities
CVE-2026-109438

3proxy 0.9.7 - 1.0.1 Uninitialized Stack Memory Disclosure via SOCKS4

3proxy 3proxy
Open in ThreatlineRecord JSON
CVSS
6.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published14 Oct 2026Updated 15 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 2

  • 3proxyaffected: 0.9.7 through 1.0.1CVE List
  • 3proxyunaffected: 206c923d6cd433bd2e7196375442650c328b8bfaCVE List

References 2