CVE-2026-44818: Microsoft Excel Remote Code Execution Vulnerability
Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
CSIRTS triage
- What
- This vulnerability allows an unauthorized attacker to execute code locally via an integer underflow.
- Who is affected
- Deployments of Microsoft Excel.
- Urgency
- Remediation is high urgency due to the high severity rating.
- Action
- Patch Microsoft Excel for CVE-2026-44818.
AI-assisted analysis generated from the source advisory — verify against the original.
⚡ Watch Microsoft Excel
Get an email when a new Microsoft Excel advisory drops — max one per day, one-click unsubscribe.
Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44818
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-448180.26% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 18% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-44818 | coverage & exploitation status | NVD · CVE.org |
More from Microsoft Security Response Center
- lowCVE-2026-14673: PostgreSQL amcheck does not clear untrusted search path2026-08-11
- criticalCVE-2026-69836: Microsoft Entra ID Remote Code Execution Vulnerability2026-08-11
- mediumCVE-2026-53792: rsync < 3.5.0 Out-of-Bounds Read via Zero-Length Checksum Block2026-08-11
- highCVE-2026-70347: Windows Installer Elevation of Privilege Vulnerability2026-08-11
- highCVE-2026-64909: Microsoft Office Remote Code Execution Vulnerability2026-08-11