How severe is CVE-2026-34339?

CVE-2026-34339 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-34339 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34339?

CVE-2026-34339 primarily affects Microsoft Windows 10 1607. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-34339?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34339 have an EU (EUVD) identifier?

Yes. CVE-2026-34339 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29598.

When was CVE-2026-34339 published?

CVE-2026-34339 was published on 2026-05-12 and last updated on 2026-06-17.

CVE-2026-34339

CVE-2026-34339 is a medium-severity vulnerability in Microsoft Windows 10 1607 with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29598
Weakness: CWE-476
Affected product: Microsoft Windows 10 1607
Published: 2026-05-12
Last modified: 2026-06-17

Description

Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an authorized attacker to deny service locally.

Frequently asked questions

What is CVE-2026-34339?: Null pointer dereference in Windows LDAP - Lightweight Directory Access Protocol allows an authorized attacker to deny service locally.
How severe is CVE-2026-34339?: CVE-2026-34339 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-34339 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34339?: CVE-2026-34339 primarily affects Microsoft Windows 10 1607. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-34339?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34339 have an EU (EUVD) identifier?: Yes. CVE-2026-34339 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29598.
When was CVE-2026-34339 published?: CVE-2026-34339 was published on 2026-05-12 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34339

Affected products (23)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

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