Source: Microsoft · Limited verification•Last verified: •Collection Degraded
CVE-2026-64903Unknown / EvaluatingCritical (raw)CVSS 7.8
Microsoft Office Remote Code Execution Vulnerability
Published: 11 Aug 2026•Last updated: 21 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
7.8Critical (raw)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Metric sourceMicrosoft MSRC CVRF
EPSS probability
0.5%0.005
Percentile39th
Weakness type
—
No further CWE recorded
Remediation
Patch status unknown
KB5002897
Why It Matters
Analysis dossierWhy It Matters
Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to execute code 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 Office 2016 (32-bit edition) · version range not provided by source · Microsoft MSRC · Source
- Microsoft Office 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 / KBKB5002897
Vendor or catalog guidance (source)
- Microsoft MSRC: Click to Run
- Microsoft MSRC: Release Notes
- Microsoft MSRC: Install the security update KB5002897 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.