CVE-2026-66810: Microsoft Office Word Information Disclosure Vulnerability
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
CSIRTS triage
- What
- A heap-based buffer overflow in Microsoft Office Word allows disclosure of sensitive information locally.
- Who is affected
- Users running affected versions of Microsoft Office Word on Windows.
- Urgency
- Medium severity (CVSS 5.5); information disclosure risk without direct code execution.
- Action
- Apply the latest security patch for Microsoft Office Word from Microsoft Update.
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-2026-66810
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-2026-668100.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-66810 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- high[NEW] [high] Microsoft Office Products: Multiple Vulnerabilitiescert-bund
- unknownMultiple vulnerabilities in Microsoft Office (August 12, 2026)cert-fr-avis
- unknownNCSC-2026-0286 [1.00] [M/H] Vulnerabilities patched in Microsoft Officencsc-nl
- mediumCVE-2026-66810: Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to disclos…nvd
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