CVE-2026-44818: Microsoft Excel Remote Code Execution Vulnerability
Integer underflow (wrap or wraparound) 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.
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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 scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-44818 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Microsoft Excel Remote
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- highCVE-2026-45469: Microsoft Excel Remote Code Execution Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-44817: Microsoft Excel Remote Code Execution Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-44820: Microsoft Excel Remote Code Execution Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-44823: Microsoft Excel Remote Code Execution Vulnerabilitymsrc · 2026-06-09
- criticalexploitedCVE-2007-0671: Microsoft Office Excel Remote Code Execution Vulnerabilitycisa-kev · 2025-08-12
- criticalexploitedCVE-2019-1297: Microsoft Excel Remote Code Execution Vulnerabilitycisa-kev · 2022-03-03
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