CVE-2026-50647 | Active Directory Federation Server Denial of Service Vulnerability

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

Published: 2026-07-14 Last update: 2026-07-16 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-50647 is rated Moderate Risk (51.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.10%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-50647

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-15 — 1.10% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-50647

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-50647

GitHub Security Advisory for CVE-2026-50647

GHSA-wcpq-cwvv-7pj4 · Severity: high — Loop with unreachable exit condition ('infinite loop') in Active Directory Federation Services ...

Affected software / configurations for CVE-2026-50647

Vendor Product Version Raw CPE
microsoft windows_10_1809 >= 10.0.17763.0, < 10.0.17763.9020 cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
microsoft windows_server_2019 >= 10.0.17763.0, < 10.0.17763.9020 cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
microsoft windows_server_2022 >= 10.0.20348.0, < 10.0.20348.5386 cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
microsoft windows_10_21H2 >= 10.0.19044.0, < 10.0.19044.7548 cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:x86:*
microsoft windows_10_22H2 >= 10.0.19045.0, < 10.0.19045.7548 cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*
microsoft windows_server_2025 >= 10.0.26100.0, < 10.0.26100.33158 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
microsoft windows_11_25H2 >= 10.0.26200.0, < 10.0.26100.8875 cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*
microsoft windows_11_24H2 >= 10.0.26100.0, < 10.0.26100.8875 cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*
microsoft windows_11_26H1 >= 10.0.28000.0, < 10.0.28000.2525 cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*
microsoft windows_10_1607 >= 10.0.14393.0, < 10.0.14393.9339 cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
microsoft windows_server_2016 >= 10.0.14393.0, < 10.0.14393.9339 cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
microsoft windows_server_2012 >= 6.2.9200.0, < 6.2.9200.26226 cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*
microsoft windows_server_2012_R2 >= 6.3.9600.0, < 6.3.9600.23291 cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*
microsoft .net >= 4.8.0, < 4.8.4803.0 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 4.8.0, < 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 4.7.0, < 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 4.7.0, < 4.7.4143.0 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 4.8.1, < 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 3.5.0, < 2.0.50727.8983 & 3.0.30729.8978 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

References for CVE-2026-50647

cvelogic Threat Intelligence