Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-66810Unknown / EvaluatingImportant (raw)CVSS 5.5
Microsoft Office Word Information Disclosure Vulnerability
Published: 11 Aug 2026•Last updated: 11 Aug 2026, 12:30 PM IST•Source identifier: Unknown
Dossier completeness: source-provided sections 3 / 3 · rule guidance not available. Missing source facts count as incomplete.
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
5.5Important (raw)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.4%0.004
Percentile36th
Weakness type
—
No further CWE recorded
Remediation
Patch status unknown
KB5002901
Why It Matters
Analysis dossierWhy It Matters
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
SOC priority
Review
Actively exploited
No
Publicly disclosed
Unknown
Risk basis: No confirmed exploitation signal in current enrichment
Affected Products & Remediation
13 source-backed productsAffected products and versions (source)
- Microsoft Office 2019 for 32-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office 2019 for 64-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft 365 Apps for Enterprise for 32-bit Systems · version range not provided by source · Microsoft MSRC · Source
- Microsoft 365 Apps for Enterprise for 64-bit Systems · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC for Mac 2021 · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC 2021 for 64-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC 2021 for 32-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC 2024 for 32-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC 2024 for 64-bit editions · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office LTSC for Mac 2024 · version range not provided by source · Microsoft MSRC · Source
- Microsoft Word 2016 (32-bit edition) · version range not provided by source · Microsoft MSRC · Source
- Microsoft Word 2016 (64-bit edition) · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office 365 for Mac · version range not provided by source · Microsoft MSRC · Source
Recorded patch / KBKB5002901
Vendor or catalog guidance (source)
- Microsoft MSRC: Click to Run
- Microsoft MSRC: Release Notes
- Microsoft MSRC: Install the security update KB5002901 listed by MSRC
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Unknown
- Exploited (source statement)
- No
- Publicly disclosed (source)
- Unknown
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
No rule-based guidance for this vulnerability class
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- Unknown
- Record status · verification
- UPDATED · Unknown
- CPE
- Unknown
Evidence & Provenance
Detection Hunting Query
— No published hunting query names this record. Browse community and library queries instead.
Correlated briefings
SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.