01 Record
CVE-2026-83646
Active Directory Federation Services (AD FS) Spoofing Vulnerability
MediumPUBLISHEDCNA: microsoft
CNA base score4.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C
02 Description
Active Directory Federation Services (AD FS) Spoofing Vulnerability
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.41% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 35.7% of scored records. A rank, not a probability.
- NVD base score
- 4.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-10-16.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-10-13 18:59Z15 DAYS AGO
- Last updated
- 2026-10-28 18:11Z15 HR AGO
- Reserved
- 2026-08-31
- Assigning CNA
- microsoft
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C
- Weaknesses
- CWE-601URL Redirection to Untrusted Site ('Open Redirect')Base
- Data version
- 5.2
- Document digest
- 736945df412008dbee3ca85f861cb2c6a739f2a1d65f7ddacd0a6824b87d0f30
05 Affected products
VendorProductVersionsPlatforms
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 to < 10.0.14393.9612x64-based Systems
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 to < 10.0.17763.9376x64-based Systems
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to < 10.0.26100.33650x64-based Systems
06 References
- msrc.microsoft.comActive Directory Federation Services (AD FS) Spoofing Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83646