CVE-2026-66809: Microsoft Office Graphics Component Information Disclosure Vulnerability
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
CSIRTS triage
- What
- Out-of-bounds read in the Graphics Component allows disclosure of local memory contents.
- Who is affected
- Users with Microsoft Office installed who open untrusted documents.
- Urgency
- Medium severity with no active exploitation; standard patch cycle applies.
- Action
- Apply the latest Microsoft Office security update when available.
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-2026-66809
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-2026-668090.28% 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-2026-66809 | 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-2026-66809: Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information…nvd
Recent advisories for Microsoft Office Graphics
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- highCVE-2026-63526: Microsoft Office Graphics Component Remote Code Execution Vulnerabilitymsrc · 2026-08-11
- highCVE-2026-63513: Microsoft Office Graphics Component Remote Code Execution Vulnerabilitymsrc · 2026-08-11
- mediumCVE-2026-63517: Microsoft Office Graphics Component Information Disclosure Vulnerabilitymsrc · 2026-08-11
- highCVE-2026-63519: Microsoft Office Graphics Component Remote Code Execution Vulnerabilitymsrc · 2026-08-11
- highCVE-2026-66807: Microsoft Office Graphics Component Remote Code Execution Vulnerabilitymsrc · 2026-08-11
- highCVE-2026-65664: Microsoft Office Graphics Component Remote Code Execution Vulnerabilitymsrc · 2026-08-11
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