Which products and versions are affected by CVE-2006-3440?

Affected: Windows 2000 (Microsoft); Windows 2003 Server (Microsoft) versions 64-bit, sp1; Windows Xp (Microsoft). The full list is in the CVE brief.

Is CVE-2006-3440 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-2006-3440 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2006-3440?

Public exploit code is available.

Is there a fix for CVE-2006-3440?

No fixed version is listed yet; check the vendor advisory for mitigations.

How urgently should CVE-2006-3440 be patched?

Brandefense priority: patch immediately, because it is very likely to be exploited soon.

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Vulnerability Intelligence

CVE-2006-3440

CriticalPublic exploit

Buffer overflow in the Winsock API in Microsoft Windows 2000 SP4, XP SP1 and SP2, and Server 2003 SP1 allows remote attackers to execute arbitrary code via unknown vectors, aka "Winsock Hostname Vulnerability."

Published Aug 8, 2006 · Updated Apr 15, 2026

Key Facts

Patch immediately

CVE-2006-3440 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Windows 2000 (Microsoft), Windows 2003 Server (Microsoft), Windows Xp (Microsoft).
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 57% probability of exploitation in the next 30 days.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

CVSS v2

10.0

AV:N/AC:L/Au:N/C:C/I:C/A:C

EPSS (30-day exploit likelihood)

57%

Higher than 99.0% of all scored CVEs

Exploited in the wild

No known

Not in a known-exploited catalog

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2006-3440 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Affected Products

7 affected entries in total

Product	Affected versions	Fixed in
Windows 2000Microsoft	See advisory	n/a
Windows 2003 ServerMicrosoft	64-bit, sp1	n/a
Windows XpMicrosoft	See advisory	n/a

Timeline

Publicly disclosed
Aug 8, 2006
Last updated
Apr 15, 2026

References

patchVU#908276
patchTA06-220A
exploitExploitDB-2900
otherMS06-041
other21394

4 more references in the full CVE brief

FAQ

Common Questions.

Buffer overflow in the Winsock API in Microsoft Windows 2000 SP4, XP SP1 and SP2, and Server 2003 SP1 allows remote attackers to execute arbitrary code via unknown vectors, aka "Winsock Hostname Vulnerability."
Affected: Windows 2000 (Microsoft); Windows 2003 Server (Microsoft) versions 64-bit, sp1; Windows Xp (Microsoft). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

Is CVE-2006-3440 Running On Your Attack Surface?

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