CVE-2019-1126
A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.To exploit this vulnerability, an attacker could run a specially crafted application, which…
Does this matter?
Lower severity and a low EPSS score (4.95%). Track it; it rarely justifies an emergency change on its own.
Description
A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.To exploit this vulnerability, an attacker could run a specially crafted application, which would allow an attacker to launch a password brute-force attack or cause account lockouts in Active Directory.This security update corrects how ADFS handles external authentication requests., aka 'ADFS Security Feature Bypass Vulnerability'. This CVE ID is unique from CVE-2019-0975.
- CVSS 3.0
- 5.3 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 4.95% probability · 92th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-307
- Affected
- microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019
- Source
- secure@microsoft.com
EPSS 4.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1126Patch, Vendor Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1126Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.