CVE-2019-1040
A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.
What it is
ReportedA tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity Check) protection. An attacker who successfully exploited this vulnerability could gain the ability to downgrade NTLM security features. To exploit this vulnerability, the attacker would need to tamper with the NTLM exchange. The attacker could then modify flags of the NTLM packet without invalidating the signature. The update addresses the vulnerability by hardening NTLM MIC protection on the server-side. Source description excerpt; complete tracked detail loads below.
NVD published: Jun 12, 2019 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026
What is affected
ReportedMicrosoft — Windows. Product-level identification only; no affected-version conclusion is available from this field.
NVD published: Jun 12, 2019 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026
Urgency and basis
ReportedAct now · 552.4
Tracker decision tier from the evidence detailed below · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026
Exploitation evidence
Reportedkev-listed · VulnCheck KEV
VulnCheck KEV added: Oct 20, 2020 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026
What to do
ReportedApply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Source remediation ↗Tracked source remediation field · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026
Evidence detail
Loading the full tracker evidence record…