How severe is CVE-2026-20833?

CVE-2026-20833 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 high, integrity none, and availability none.

Is CVE-2026-20833 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20833?

CVE-2026-20833 primarily affects Microsoft Windows Server 2008. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20833?

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

Does CVE-2026-20833 have an EU (EUVD) identifier?

Yes. CVE-2026-20833 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2153.

When was CVE-2026-20833 published?

CVE-2026-20833 was published on 2026-01-13 and last updated on 2026-06-17.

CVE-2026-20833

CVE-2026-20833 is a medium-severity vulnerability in Microsoft Windows Server 2008 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-327.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2153
Weakness: CWE-327
Affected product: Microsoft Windows Server 2008
Published: 2026-01-13
Last modified: 2026-06-17

Description

Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.

Frequently asked questions

What is CVE-2026-20833?: Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.
How severe is CVE-2026-20833?: CVE-2026-20833 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 high, integrity none, and availability none.
Is CVE-2026-20833 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20833?: CVE-2026-20833 primarily affects Microsoft Windows Server 2008. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20833?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-20833 have an EU (EUVD) identifier?: Yes. CVE-2026-20833 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2153.
When was CVE-2026-20833 published?: CVE-2026-20833 was published on 2026-01-13 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833

Affected products (10)

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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