September 2026 Patch TuesdayMSRC-2026-09-microsoft-office-release-notesNormal patch window

Microsoft · MSRC-2026-09-microsoft-office-release-notes

Linked CVE review

Deploy Microsoft Microsoft Office update for Microsoft Office LTSC for Mac 2021

Linked CVEs: 11
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.

11 of 11 linked CVEs shown

Confirmed exploitedCVSS above 9.0

CVE and description	Severity	Exploit reality	Forecast and access	Remediation
CVE-2026-78505 Scheduled assessment Microsoft Office Remote Code Execution Vulnerability Heap-based buffer overflow in Microsoft Office 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: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED 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.
CVE-2026-78526 Scheduled assessment Microsoft Office Word Remote Code Execution Vulnerability Heap-based buffer overflow in Microsoft Office Word 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% · 56.0th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Patch available. 16.0.10417.20207:Security Update:https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
CVE-2026-69626 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Buffer over-read in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-78515 Scheduled assessment Microsoft Office Excel Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80076 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80078 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80082 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80086 Scheduled assessment Microsoft Office PowerPoint Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office PowerPoint allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80089 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-80091 Scheduled assessment Microsoft Office Information Disclosure Vulnerability Use of uninitialized resource in Microsoft Office allows an unauthorized attacker to disclose information over a network.	6.5 · CVSS 3.1 · MediumSource: 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: 0.92% · 59.2th percentileForecast date: 2026-10-09NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.
CVE-2026-78513 Scheduled assessment Microsoft Office PowerPoint Information Disclosure Vulnerability Out-of-bounds read in Microsoft Office PowerPoint allows an unauthorized attacker to disclose information locally.	5.5 · CVSS 3.1 · MediumSource: 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: 0.54% · 43.8th percentileForecast date: 2026-10-09LOCAL · LOW complexity · NONE privileges · REQUIRED user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.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.