CVE-2026-44818
Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- CVSS 3.1
- 7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.26% probability · 18th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-362
- Affected
- microsoft/365 apps · microsoft/excel · microsoft/microsoft 365 · microsoft/office 2019 · microsoft/office 2021 · microsoft/office 2024 · microsoft/office online server
- Source
- secure@microsoft.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.