Microsoft Windows up to Server 2025 Ancillary Function Driver for WinSock use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.1$5k-$25k0.00

Summaryinfo

A vulnerability was found in Microsoft Windows and classified as critical. This vulnerability affects unknown code of the component Ancillary Function Driver for WinSock. Such manipulation leads to use after free. This vulnerability is documented as CVE-2026-33100. The attack needs to be performed locally. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Microsoft Windows. Affected by this issue is an unknown code of the component Ancillary Function Driver for WinSock. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability.

The weakness was released 04/14/2026 as confirmed security update guide (Website). The advisory is shared for download at msrc.microsoft.com. This vulnerability is handled as CVE-2026-33100. The exploitation is known to be difficult. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 06/01/2026).

Upgrading to version 6.2.9200.26026, 6.3.9600.23132, 10.0.14393.9060, 10.0.17763.8644, 10.0.19044.7184, 10.0.19045.7184, 10.0.20348.5020, 10.0.22631.6936, 10.0.25398.2274, 10.0.26100.32690, 10.0.26200.8246 or 10.0.28000.1836 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1730). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Xerox FreeFlow Print Server

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.1

VulDB Base Score: 7.0
VulDB Temp Score: 6.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.0
Vendor Vector (Microsoft): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Upgrade: Windows 6.2.9200.26026/6.3.9600.23132/10.0.14393.9060/10.0.17763.8644/10.0.19044.7184/10.0.19045.7184/10.0.20348.5020/10.0.22631.6936/10.0.25398.2274/10.0.26100.32690/10.0.26200.8246/10.0.28000.1836

Timelineinfo

04/14/2026 VulDB entry created
04/14/2026 +0 days Advisory disclosed
04/14/2026 +0 days Countermeasure disclosed
06/01/2026 +47 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-33100 (🔒)
GCVE (CVE): GCVE-0-2026-33100
GCVE (VulDB): GCVE-100-357536
CERT Bund: WID-SEC-2026-1730 - Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 04/14/2026 20:50
Updated: 06/01/2026 07:29
Changes: 04/14/2026 20:50 (32), 04/14/2026 20:51 (5), 04/14/2026 20:54 (33), 06/01/2026 07:29 (7)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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