CVE-2026-78503
published 2026-09-08CVE-2026-78503: Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
PriorityP338medium6.5CVSS 3.1
AVNACLPRNUIRSUCHINAN
EPSS
0.92%
58.3th percentile
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft_365_apps_for_enterprise | >= 16.0.1 < 16.0.20326.20138 | 16.0.20326.20138 |
| microsoft | microsoft_office_2019 | >= 19.0.0 < 16.0.10417.20207 | 16.0.10417.20207 |
| microsoft | microsoft_office_365_for_mac | — | — |
| microsoft | microsoft_office_ltsc_2021 | >= 16.0.1 < 16.0.14334.20906 | 16.0.14334.20906 |
| microsoft | microsoft_office_ltsc_2024 | >= 16.0.0 < 16.0.17932.20976 | 16.0.17932.20976 |
| microsoft | microsoft_office_ltsc_for_mac_2021 | — | — |
| microsoft | microsoft_office_ltsc_for_mac_2024 | — | — |
| microsoft | microsoft_word_2016 | >= 16.0.1 < 16.0.5569.1000 | 16.0.5569.1000 |
| microsoft | word | — | — |
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VulDB
Microsoft Office memory corruption (Nessus ID 344562)
vuldb·2026-09-11·CVSS 6.5
CVE-2026-78503 [MEDIUM] Microsoft Office memory corruption (Nessus ID 344562)
A vulnerability labeled as problematic has been found in Microsoft Office. The affected element is an unknown function. Such manipulation leads to memory corruption.
This vulnerability is uniquely identified as CVE-2026-78503. The attack can be launched remotely. No exploit exists.
A patch should be applied to remediate this issue.
GHSA
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
ghsa_unreviewed·2026-09-08
CVE-2026-78503 [MEDIUM] CWE-125 Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
No detection rules found.
No public exploits indexed.
Sans Isc
September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)
blogs_sans_isc·2026-09-08·CVSS 7.8
CVE-2026-81963 [HIGH] September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)
September 2026 Microsoft Patch Tuesday
Published: 2026-09-08. Last Updated: 2026-09-08 19:20:30 UTC
by Johannes Ullrich (Version: 1)
0 comment(s)
This month, Microsoft released patches for a record-breaking 973 vulnerabilities, including 113 rated critical. It is by far the largest Patch Tuesday to date, well ahead of the previous high of 664 set in July 2026. Two vulnerabilities are listed as exploited in the wild, while none were publicly disclosed before Patch Tuesday. Notable fixes include Windows privilege escalation and critical RCEs in Skype for Business, MSMQ and RRAS.
A few vulnerabilities worth mentioning:
Windows Update Stack Elevation of Privilege Vulnerability (CVE-2026-81963)
Microsoft reports that CVE-2026-81963 is being exploited, though it was not publicly disclosed b
Rapid7
Patch Tuesday - September 2026
blogs_rapid7·2026-09-08·CVSS 7.8
CVE-2026-85880 [HIGH] Patch Tuesday - September 2026
Microsoft is publishing 974 own-product vulnerabilities on September 2026 Patch Tuesday , including 723 vulnerabilities in Windows. Along with Microsoft fixes for 25 non-Microsoft CVEs, that brings the total number of vulnerabilities on the table today to 999. Whether this is the biggest Patch Tuesday ever depends on how we count, but this is by far the most CVEs that Microsoft has ever published in a single day. As Rapid7 noted last month, there is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for two of the vulnerabilities published today.
## Windows ALPC: zero-day EoP
The eternal game of elevation of privilege whack-a-mole between Microsoft and attackers continues. This month, the batt
2026-09-08
Published