Which products and versions are affected by CVE-2009-2526?

Affected: Windows Server 2008 (Microsoft); Windows Vista (Microsoft). The full list is in the CVE brief.

Is CVE-2009-2526 being exploited in the wild?

It is exploited in the wild, listed in Industry KEV feed since Jun 20, 2017.

Is CVE-2009-2526 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-2009-2526?

Public exploit code is available.

Is there a fix for CVE-2009-2526?

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

How urgently should CVE-2009-2526 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

Request A Demo

Vulnerability Intelligence

CVE-2009-2526

HighExploitedPublic exploit

Microsoft Windows Vista Gold, SP1, and SP2 and Server 2008 Gold and SP2 do not properly validate fields in SMBv2 packets, which allows remote attackers to cause a denial of service (infinite loop and system hang) via a crafted packet to the Server service, aka "SMBv2 Infinite…

Published Oct 14, 2009 · Updated Apr 22, 2026

Key Facts

Patch immediately

CVE-2009-2526 is a high-severity vulnerability (CVSS 7.8 v2) affecting Windows Server 2008 (Microsoft), Windows Vista (Microsoft).
It is exploited in the wild, listed in Industry KEV feed since Jun 20, 2017. Public exploit code is available.
EPSS estimates a 82% 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 listed as exploited in the wild.

CVSS v2

7.8

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

EPSS (30-day exploit likelihood)

82%

Higher than 99.6% of all scored CVEs

Exploited in the wild

Yes

1 catalog listing

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2009-2526 brief as a PDF

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

Description

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
Industry KEV feed	Jun 20, 2017	n/a	Not reported

Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected Products

14 affected entries in total

Product	Affected versions	Fixed in
Windows Server 2008Microsoft	See advisory	n/a
Windows VistaMicrosoft	See advisory	n/a

Timeline

Publicly disclosed
Oct 14, 2009
Added to Industry KEV feed
Jun 20, 2017
Last updated
Apr 22, 2026

Weakness Type

CWE-399

References

1 more references in the full CVE brief

FAQ

Common Questions.

Microsoft Windows Vista Gold, SP1, and SP2 and Server 2008 Gold and SP2 do not properly validate fields in SMBv2 packets, which allows remote attackers to cause a denial of service (infinite loop and system hang) via a crafted packet to the Server service, aka "SMBv2 Infinite Loop Vulnerability."
Affected: Windows Server 2008 (Microsoft); Windows Vista (Microsoft). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jun 20, 2017.
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 listed as exploited in the wild.

Is CVE-2009-2526 Running On Your Attack Surface?

Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.