PatchSiren cyber security CVE debrief
CVE-2026-44817 Microsoft CVE debrief
CVE-2026-44817 is a HIGH severity vulnerability in Microsoft Office Excel. An integer underflow (or, wrap/wraparound) vulnerability exists, which could allow an unauthorized attacker to execute code locally. The vulnerability has a CVSS score of 7.8 and was published on [cvePublishedAt](https://www.cve.org/CVERecord?id=CVE-2026-44817).
- Vendor
- Microsoft
- Product
- Microsoft 365 Apps for Enterprise
- CVSS
- HIGH 7.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-09
- Original CVE updated
- 2026-06-11
- Advisory published
- 2026-06-09
- Advisory updated
- 2026-06-11
Who should care
Users of Microsoft Office Excel, particularly those using vulnerable versions, should apply patches or mitigations to prevent local code execution.
Technical summary
The vulnerability exists in Microsoft Office Excel due to an integer underflow (or, wrap/wraparound). This could allow an attacker to execute code locally. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 7.8, indicating a HIGH severity level.
Defensive priority
HIGH
Recommended defensive actions
- Apply patches or updates provided by Microsoft to vulnerable versions of Microsoft Office Excel.
- Use secure practices when opening Excel files from untrusted sources.
Evidence notes
The CVE-2026-44817 vulnerability was published on [cvePublishedAt](https://www.cve.org/CVERecord?id=CVE-2026-44817) and modified on [cveModifiedAt](https://nvd.nist.gov/vuln/detail/CVE-2026-44817).
Official resources
-
CVE-2026-44817 CVE record
CVE.org
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CVE-2026-44817 NVD detail
NVD
-
Source item URL
nvd_modified
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Mitigation or vendor reference
[email protected] - Vendor Advisory
CVE-2026-44817 was published on 2026-06-09T17:17:17.890Z and modified on 2026-06-11T18:38:23.970Z.