CVE-2026-20957
Microsoft Excel Remote Code Execution Vulnerability
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- 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 Excel Remote Code Execution Vulnerability
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-20957- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness
- CWE-191, CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-2103
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
EUVD-2026-2103- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/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-wv7r-h676-ghph
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker...
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
GHSA-wv7r-h676-ghph- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-20957- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122, CWE-191
- Updated
- 2026-11-02
Affected products
- microsoft excel
- microsoft office
- microsoft 365 apps
- microsoft 365 apps for enterprise
- microsoft excel 2016
- microsoft office 2019
- microsoft office ltsc 2021
- microsoft office ltsc 2024
- microsoft office ltsc for mac 2021
- microsoft office ltsc for mac 2024
- microsoft office online server
- microsoft office long term servicing channel
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-20957 is a high vulnerability (CVSS 7.8) in Microsoft Excel, published January 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.51%, the 43rd percentile. No source names a fixed version.