CVE-2026-64899
Microsoft Office Information Disclosure Vulnerability
No known exploitation. EPSS puts it in the 43rd percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 43rd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
8 events over 3 days, from the signal feeds we watch.
- Patch availablerecord updated
- OpenVAS check added
- Publishedweakness classified, att&ck mapped, record updated, record updated
Affected products
- Microsoft 365 Apps for EnterpriseConsumer Software / productivity
- Microsoft Office LTSC 2021Consumer Software / productivity
- Microsoft Office 365 for MacConsumer Software / productivity
- Microsoft Office LTSC for Mac 2021Consumer Software / productivity
- Microsoft Office LTSC for Mac 2024Consumer Software / productivity
- microsoft 365Cloud & SaaS / saas-application
- office 2016Consumer Software / productivity
- office 2019Consumer Software / productivity
And 6 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Scored 5.5 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity NoneNo integrity impact
- Availability NoneNo availability impact
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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