September 2026 Patch TuesdayMSRC-2026-09-windows-release-notesNormal patch window

Microsoft · MSRC-2026-09-windows-release-notes

Linked CVE review

Deploy Microsoft Windows update for Remote Desktop client for Windows Desktop

Linked CVEs: 4
Confirmed exploited: 0
PoC or lab evidence: 0
Maximum CVSS: 8.8

Evidence is kept separate

Confirmed exploitation, public exploit material, EPSS probability and CVSS severity answer different questions. “No confirmation recorded” means the checked sources do not currently confirm exploitation. It is not proof that exploitation has not occurred.

4 of 4 linked CVEs shown

Confirmed exploitedCVSS above 9.0

CVE and description	Severity	Exploit reality	Forecast and access	Remediation
CVE-2026-78463 Scheduled assessment Remote Desktop Client Remote Code Execution Vulnerability Improper control of generation of code ('code injection') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.	8.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.86% · 57.3th percentileForecast date: 2026-10-08NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Mitigation available. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-80074 Scheduled assessment Remote Desktop Client Remote Code Execution Vulnerability Heap-based buffer overflow in Remote Desktop Client allows an unauthorized attacker to execute code over a network.	8.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.82% · 55.9th percentileForecast date: 2026-10-08NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Mitigation available. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-80077 Scheduled assessment Remote Desktop Client Remote Code Execution Vulnerability Heap-based buffer overflow in Remote Desktop Client allows an unauthorized attacker to execute code over a network.	8.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.82% · 55.9th percentileForecast date: 2026-10-08NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Mitigation available. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-57098 Scheduled assessment Microsoft Remote Desktop App for Windows Information Disclosure Vulnerability Improper verification of cryptographic signature in Windows RDP Client allows an unauthorized attacker to disclose information over a network.	7.5 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.64% · 49.0th percentileForecast date: 2026-10-08NETWORK · LOW complexity · NONE privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Patch available. An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.