How severe is CVE-2026-20834?

CVE-2026-20834 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-20834 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20834?

CVE-2026-20834 primarily affects Microsoft Windows 10 1607. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20834?

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

Does CVE-2026-20834 have an EU (EUVD) identifier?

Yes. CVE-2026-20834 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2156.

When was CVE-2026-20834 published?

CVE-2026-20834 was published on 2026-01-13 and last updated on 2026-06-17.

CVE-2026-20834

CVE-2026-20834 is a medium-severity vulnerability in Microsoft Windows 10 1607 with a CVSS 3.x base score of 4.6. 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-36.

Key facts

Severity: Medium (CVSS 3.x base score 4.6)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2156
Weakness: CWE-36
Affected product: Microsoft Windows 10 1607
Published: 2026-01-13
Last modified: 2026-06-17

Description

Absolute path traversal in Windows Shell allows an unauthorized attacker to perform spoofing with a physical attack.

Frequently asked questions

What is CVE-2026-20834?: Absolute path traversal in Windows Shell allows an unauthorized attacker to perform spoofing with a physical attack.
How severe is CVE-2026-20834?: CVE-2026-20834 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-20834 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20834?: CVE-2026-20834 primarily affects Microsoft Windows 10 1607. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20834?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-20834 have an EU (EUVD) identifier?: Yes. CVE-2026-20834 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2156.
When was CVE-2026-20834 published?: CVE-2026-20834 was published on 2026-01-13 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20834

Affected products (19)

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:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
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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