CVE-2026-34346

Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability

Products / packages Microsoft Windows 10 Version 1607 · Microsoft Windows 10 Version 1809 · Microsoft Windows 10 Version 21H2 · 17 more

Published 14/07/2026, 17:04:19 UTC

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 05/11/2026, 13:55:32 UTC

microsoft · CVSS:3.1 · 5.5

Assessment vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Severity

medium5.5

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

The Windows Ancillary Function Driver for WinSock has a vulnerability that allows an authorized attacker to disclose sensitive information locally due to cleartext transmission. Affected versions include various Windows 10 and Windows Server releases. The weakness is described as cleartext transmission of sensitive information.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Microsoft · microsoft

Windows 10 Version 1607

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.14393.0 → before 10.0.14393.9339

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 10 Version 1809

1 range

microsoft version evidence

Platforms: 32-bit Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.17763.0 → before 10.0.17763.9020

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 10 Version 21H2

1 range

microsoft version evidence

Platforms: 32-bit Systems, ARM64-based Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.19044.0 → before 10.0.19044.7548

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 10 Version 22H2

1 range

microsoft version evidence

Platforms: 32-bit Systems, ARM64-based Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.19045.0 → before 10.0.19045.7548

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 11 version 23H2

1 range

microsoft version evidence

Platforms: ARM64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.22631.0 → before 10.0.22631.7376

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 11 Version 23H2

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.22631.0 → before 10.0.22631.7376

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 11 Version 24H2

1 range

microsoft version evidence

Platforms: ARM64-based Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.26100.0 → before 10.0.26100.8875

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 11 Version 25H2

1 range

microsoft version evidence

Platforms: ARM64-based Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.26200.0 → before 10.0.26200.8875

custom versions

Other versions: unknown

Microsoft · microsoft

Windows 11 version 26H1

1 range

microsoft version evidence

Platforms: ARM64-based Systems, x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.28000.0 → before 10.0.28000.2525

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2012

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

6.2.9200.0 → before 6.2.9200.26226

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2012 (Server Core installation)

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

6.2.9200.0 → before 6.2.9200.26226

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2012 R2

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

6.3.9600.0 → before 6.3.9600.23291

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2012 R2 (Server Core installation)

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

6.3.9600.0 → before 6.3.9600.23291

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2016

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.14393.0 → before 10.0.14393.9339

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2016 (Server Core installation)

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.14393.0 → before 10.0.14393.9339

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2019

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.17763.0 → before 10.0.17763.9020

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2019 (Server Core installation)

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.17763.0 → before 10.0.17763.9020

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2022

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.20348.0 → before 10.0.20348.5386

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2025

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.26100.0 → before 10.0.26100.33158

custom versions

Other versions: unknown

Microsoft · microsoft

Windows Server 2025 (Server Core installation)

1 range

microsoft version evidence

Platforms: x64-based Systems

Check a product version

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.26100.0 → before 10.0.26100.33158

custom versions

Other versions: unknown

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

Cleartext transmission of sensitive information in Windows Ancillary Function Driver for WinSock allows an authorized attacker to disclose information locally.

References

1 sources

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34346

Vendor advisorymicrosoft

Inside the record

Evidence available

Package identity · not supplied

Version evidence

Remediation guidance · not supplied

Weakness classification

Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-34346

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-319 ↗

CWE-319: Cleartext Transmission of Sensitive Information

microsoft

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

microsoft · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*

From (inclusive): 10.0.17763.0

After:

Through (inclusive):

Before: 10.0.17763.9020

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*

From (inclusive): 10.0.17763.0

After:

Through (inclusive):

Before: 10.0.17763.9020

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*

From (inclusive): 10.0.17763.0

After:

Through (inclusive):

Before: 10.0.17763.9020

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*

From (inclusive): 10.0.20348.0

After:

Through (inclusive):

Before: 10.0.20348.5386

Vulnerable product

cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:x86:*

From (inclusive): 10.0.19044.0

After:

Through (inclusive):

Before: 10.0.19044.7548

Vulnerable product

cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*

From (inclusive): 10.0.19045.0

After:

Through (inclusive):

Before: 10.0.19045.7548

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

From (inclusive): 10.0.26100.0

After:

Through (inclusive):

Before: 10.0.26100.33158

Vulnerable product

cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*

From (inclusive): 10.0.26200.0

After:

Through (inclusive):

Before: 10.0.26200.8875

Vulnerable product

cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*

From (inclusive): 10.0.22631.0

After:

Through (inclusive):

Before: 10.0.22631.7376

Vulnerable product

cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*

From (inclusive): 10.0.22631.0

After:

Through (inclusive):

Before: 10.0.22631.7376

Vulnerable product

cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*

From (inclusive): 10.0.26100.0

After:

Through (inclusive):

Before: 10.0.26100.8875

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

From (inclusive): 10.0.26100.0

After:

Through (inclusive):

Before: 10.0.26100.33158

Vulnerable product

cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*

From (inclusive): 10.0.28000.0

After:

Through (inclusive):

Before: 10.0.28000.2525

Vulnerable product

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*

From (inclusive): 10.0.14393.0

After:

Through (inclusive):

Before: 10.0.14393.9339

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*

From (inclusive): 10.0.14393.0

After:

Through (inclusive):

Before: 10.0.14393.9339

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*

From (inclusive): 10.0.14393.0

After:

Through (inclusive):

Before: 10.0.14393.9339

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*

From (inclusive): 6.2.9200.0

After:

Through (inclusive):

Before: 6.2.9200.26226

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*

From (inclusive): 6.2.9200.0

After:

Through (inclusive):

Before: 6.2.9200.26226

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*

From (inclusive): 6.3.9600.0

After:

Through (inclusive):

Before: 6.3.9600.23291

Vulnerable product

cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*

From (inclusive): 6.3.9600.0

After:

Through (inclusive):

Before: 6.3.9600.23291

Original applicability statements

[
  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*",
            "versionStartIncluding": "10.0.17763.0",
            "versionEndExcluding": "10.0.17763.9020"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.17763.0",
            "versionEndExcluding": "10.0.17763.9020"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.17763.0",
            "versionEndExcluding": "10.0.17763.9020"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.20348.0",
            "versionEndExcluding": "10.0.20348.5386"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:x86:*",
            "versionStartIncluding": "10.0.19044.0",
            "versionEndExcluding": "10.0.19044.7548"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "10.0.19045.0",
            "versionEndExcluding": "10.0.19045.7548"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.26100.0",
            "versionEndExcluding": "10.0.26100.33158"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*",
            "versionStartIncluding": "10.0.26200.0",
            "versionEndExcluding": "10.0.26200.8875"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*",
            "versionStartIncluding": "10.0.22631.0",
            "versionEndExcluding": "10.0.22631.7376"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "10.0.22631.0",
            "versionEndExcluding": "10.0.22631.7376"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*",
            "versionStartIncluding": "10.0.26100.0",
            "versionEndExcluding": "10.0.26100.8875"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.26100.0",
            "versionEndExcluding": "10.0.26100.33158"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "10.0.28000.0",
            "versionEndExcluding": "10.0.28000.2525"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*",
            "versionStartIncluding": "10.0.14393.0",
            "versionEndExcluding": "10.0.14393.9339"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.14393.0",
            "versionEndExcluding": "10.0.14393.9339"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.14393.0",
            "versionEndExcluding": "10.0.14393.9339"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "6.2.9200.0",
            "versionEndExcluding": "6.2.9200.26226"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "6.2.9200.0",
            "versionEndExcluding": "6.2.9200.26226"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "6.3.9600.0",
            "versionEndExcluding": "6.3.9600.23291"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*",
            "versionStartIncluding": "6.3.9600.0",
            "versionEndExcluding": "6.3.9600.23291"
          }
        ]
      }
    ]
  }
]

Contributing organizations · 2

microsoft

Assigning organization

2026-11-01

CISA-ADP

Additional data publisher

2026-07-15

Timeline

All times UTC

14 Jul 2026, 17:04
Advisory published
Publication date supplied by the source.
1 Nov 2026, 17:32
Source updated
Latest modification date supplied by the source.
1 Nov 2026, 17:41
Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes

No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.

Reading the signals

Severity · CVSS: Technical impact and attack conditions. The headline is the highest imported catalog score; sources may disagree.
Observed exploitation · KEV: An absent or unavailable KEV listing does not establish that exploitation has not occurred.
Predicted exploitation · EPSS: 0.27% estimated probability in the next 30 days. 2026-11-01 · FIRST EPSS.

CISA-ADP · SSVC

CISA Coordinator · 2026-07-15

Exploitation: none
Automatable: no
Technical Impact: partial

SSVC describes the publisher’s decision context. Your organization’s exposure and priorities may differ.

Record identifiers

Aliases: None recorded

Source evidence

Request a correction or dispute

Start with the assigning organization for this record. Include the CVE ID, the disputed information, and supporting evidence. A dispute does not itself reject a record.

Find the responsible CNA →Official dispute and escalation process ↗

CVE CVE-2026-34346

Enrichment coverage

NVDAvailable

Checked 02/11/2026, 10:45:33 UTC

GHSAAvailable

Checked 02/11/2026, 10:45:33 UTC

EUVDAvailable

Checked 02/11/2026, 10:45:33 UTC

EPSSAvailable

Checked 02/11/2026, 10:45:33 UTC

Additional source evidence

NVD · CVE-2026-34346

CVSS 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Checked 02/11/2026, 10:45:33 UTC

ENISA EUVD · EUVD-2026-43969

CVSS 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Checked 02/11/2026, 10:45:33 UTC

FIRST EPSS · CVE-2026-34346

EPSS 0.27% probability of exploitation in the next 30 days. Percentile: 19.23% · 2026-11-01

Checked 02/11/2026, 10:45:33 UTC

GitHub Advisory Database · GHSA-46c5-ppqr-v898

CVSS 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Checked 02/11/2026, 10:45:33 UTC

Sponsored by MoxsoBuild security habits with adaptive training and phishing simulations.View as JSON

Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability

Severity and exploitation

What this means

Attack conditions

Affected versions

Windows 10 Version 1607

affected

unaffected

unknown

Windows 10 Version 1809

affected

unaffected

unknown

Windows 10 Version 21H2

affected

unaffected

unknown

Windows 10 Version 22H2

affected

unaffected

unknown

Windows 11 version 23H2

affected

unaffected

unknown

Windows 11 Version 23H2

affected

unaffected

unknown

Windows 11 Version 24H2

affected

unaffected

unknown

Windows 11 Version 25H2

affected

unaffected

unknown

Windows 11 version 26H1

affected

unaffected

unknown

Windows Server 2012

affected

unaffected

unknown

Windows Server 2012 (Server Core installation)

affected

unaffected

unknown

Windows Server 2012 R2

affected

unaffected

unknown

Windows Server 2012 R2 (Server Core installation)

affected

unaffected

unknown

Windows Server 2016

affected

unaffected

unknown

Windows Server 2016 (Server Core installation)

affected

unaffected

unknown

Windows Server 2019

affected

unaffected

unknown

Windows Server 2019 (Server Core installation)

affected

unaffected

unknown

Windows Server 2022

affected

unaffected

unknown

Windows Server 2025

affected

unaffected