First day on Intigriti: our agent harness found and proved a remote code execution bug, paid €3,000.

CVE-2026-78503

MediumCVSS 6.5/10Last modified Sep 17, 2026

Description

Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.

Metrics

CVSS 3.1 6.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Weakness enumeration

Affected software

Vendor	Product	Versions
Microsoft	Microsoft 365 Apps for Enterprise	>= 16.0.1, < 16.0.20326.20138
Microsoft	Microsoft Office 2019	>= 19.0.0, < 16.0.10417.20207
Microsoft	Microsoft Office 365 for Mac	>= 1.0.0, < 16.113.26091433
Microsoft	Microsoft Office LTSC 2021	>= 16.0.1, < 16.0.14334.20906
Microsoft	Microsoft Office LTSC 2024	>= 16.0.0, < 16.0.17932.20976
Microsoft	Microsoft Office LTSC for Mac 2021	>= 16.0.1, < 16.113.26091433
Microsoft	Microsoft Office LTSC for Mac 2024	>= 16.0.0, < 16.113.26091433
Microsoft	Microsoft Word 2016	>= 16.0.1, < 16.0.5569.1000

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78503Patch, Vendor Advisory

Timeline

Published: Sep 8, 2026
Last modified: Sep 17, 2026
NVD status: Analyzed

Related CVEs from 2026

CVE-2026-785048.8Stack-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.CVE-2026-785058.8Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.CVE-2026-785065.5Improper null termination in Microsoft Office Word allows an unauthorized attacker to disclose information locally.CVE-2026-785078.8Use after free in Microsoft Office Word allows an unauthorized attacker to execute code over a network.CVE-2026-785084.6Out-of-bounds read in Windows CD-ROM Driver allows an unauthorized attacker to disclose information with a physical attack.CVE-2026-785099.8Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.CVE-2026-78517.2A vulnerability was identified in D-Link DI-8100 16.07.26A1. This affects the function sprintf of the file yyxz.asp. The manipulation of the CVE-2026-785108.4Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.CVE-2026-785118.8Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.CVE-2026-785128.8Numeric truncation error in Microsoft Office Word allows an unauthorized attacker to execute code over a network.CVE-2026-785135.5Out-of-bounds read in Microsoft Office PowerPoint allows an unauthorized attacker to disclose information locally.CVE-2026-785148.8Use after free in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

CVE-2026-78503: Medium severity, CVSS 6.5 | Vulnix