CVE-2026-55031: Microsoft Excel Remote Code Execution Vulnerability
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
CSIRTS triage
- What
- Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Who is affected
- Users of Microsoft Excel.
- Urgency
- Remediation is urgent due to the high severity and potential for remote code execution.
- Action
- Update Microsoft Excel to the latest version to mitigate the vulnerability.
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-2026-55031
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-2026-550310.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 32% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-55031 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- critical[NEW] [critical] Microsoft Office products: Multiple vulnerabilitiescert-bund
- unknownexploitedNCSC-2026-0237 [1.02] [H/H] Vulnerabilities Fixed in Microsoft Officencsc-nl
- unknownexploitedNCSC-2026-0237 [1.01] [H/H] Vulnerabilities fixed in Microsoft Officencsc-nl
- unknownMultiple vulnerabilities in Microsoft Office (July 15, 2026)cert-fr-avis
- unknownexploitedNCSC-2026-0237 [1.00] [M/H] Vulnerabilities fixed in Microsoft Officencsc-nl
- highCVE-2026-55031: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code l…nvd
More from Microsoft Security Response Center
- highCVE-2026-42900: Microsoft Windows App Store Elevation of Privilege Vulnerability2026-07-14
- mediumCVE-2026-55003: Windows Remote Desktop Protocol (RDP) Information Disclosure Vulnerability2026-07-14
- highCVE-2026-57992: Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability2026-07-14
- unknownCVE-2026-13867: Chromium: CVE-2026-13867 Inappropriate implementation in Geolocation2026-07-14
- mediumCVE-2026-59926: Mistune: XSS via unescaped class option in Admonition directive2026-07-14