CVE-2026-50647

Active Directory Federation Server Denial of Service Vulnerability

At a glance

Severity: HIGH 7.5
EPSS: EPSS 1.17 % · percentile 67 (2026-10-27)
State: PUBLISHED
Published: 2026-07-14
Updated: 2026-10-08
Assigner: microsoft
NVD status: Analyzed

Description

Loop with unreachable exit condition ('infinite loop') in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C	microsoft
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · secure@microsoft.com (Secondary)

Weaknesses (CWE)

CWE-835

European references

ENISA EUVD · EUVD-2026-44118
GCVE · GCVE-0-2026-50647

CERT-FR advisories

CERTFR-2026-AVI-0869 — Multiples vulnérabilités dans Microsoft Windows · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:* < 10.0.14393.9339
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:* < 10.0.14393.9339
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* < 10.0.17763.9020
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* < 10.0.17763.9020
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:* < 10.0.19044.7548
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:* < 10.0.19044.7548
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:* < 10.0.19044.7548
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:* < 10.0.19045.7548
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:* < 10.0.19045.7548
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:* < 10.0.19045.7548
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* < 10.0.26100.8875
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* < 10.0.26100.8875
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* < 10.0.26200.8875
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* < 10.0.26200.8875
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* < 10.0.28000.2525
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* < 10.0.28000.2525
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:*:*:*:*:*:*:*:* < 10.0.14393.9339
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* < 10.0.17763.9020
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* < 10.0.20348.5386
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* < 10.0.26100.33158
cpe:2.3:a:microsoft:.net_framework:4.8.1:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.6.2:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7.1:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.8.1:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:*

Affected products

Product	Versions
Microsoft · Microsoft .NET Framework 3.5 AND 4.7.2	affected 4.7.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0
Microsoft · Microsoft .NET Framework 3.5 AND 4.8	affected 4.8.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0
Microsoft · Microsoft .NET Framework 3.5 AND 4.8.1	affected 4.8.1 < 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0
Microsoft · Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2	affected 4.7.0 < 4.7.4143.0
Microsoft · Microsoft .NET Framework 4.8	affected 4.8.0 < 4.8.4803.0
Microsoft · Microsoft .NET Framework 4.8.1	affected 4.8.0.0 < 4.8.9340.0
Microsoft · Windows 10 Version 1607	affected 10.0.14393.0 < 10.0.14393.9339
Microsoft · Windows 10 Version 1809	affected 10.0.17763.0 < 10.0.17763.9020
Microsoft · Windows 10 Version 21H2	affected 10.0.19044.0 < 10.0.19044.7548
Microsoft · Windows 10 Version 22H2	affected 10.0.19045.0 < 10.0.19045.7548
Microsoft · Windows 11 Version 24H2	affected 10.0.26100.0 < 10.0.26100.8875
Microsoft · Windows 11 Version 25H2	affected 10.0.26200.0 < 10.0.26200.8875
Microsoft · Windows 11 version 26H1	affected 10.0.28000.0 < 10.0.28000.2525
Microsoft · Windows Server 2012	affected 6.2.9200.0 < 6.2.9200.26226
Microsoft · Windows Server 2012 (Server Core installation)	affected 6.2.9200.0 < 6.2.9200.26226
Microsoft · Windows Server 2012 R2	affected 6.3.9600.0 < 6.3.9600.23291
Microsoft · Windows Server 2012 R2 (Server Core installation)	affected 6.3.9600.0 < 6.3.9600.23291
Microsoft · Windows Server 2016	affected 10.0.14393.0 < 10.0.14393.9339
Microsoft · Windows Server 2016 (Server Core installation)	affected 10.0.14393.0 < 10.0.14393.9339
Microsoft · Windows Server 2019	affected 10.0.17763.0 < 10.0.17763.9020

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50647

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD