CVE-2026-78505
Microsoft Office Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Office Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
- Record
CVE-2026-78505- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-73307
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
- Record
EUVD-2026-73307- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6hj5-28cq-px6j
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code...
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
- Record
GHSA-6hj5-28cq-px6j- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
- Record
CVE-2026-78505- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-78505 is a high vulnerability (CVSS 8.8) in Microsoft 365 Apps, published September 8, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.82%, the 57th percentile. No source names a fixed version.