CVE-2026-63529: Microsoft Office Information Disclosure Vulnerability
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
CSIRTS triage
- What
- An out-of-bounds read in Microsoft Office allows local information disclosure.
- Who is affected
- Local users on systems running Microsoft Office are affected.
- Urgency
- Low to moderate urgency; CVSS 5.5 medium severity information disclosure requiring local access.
- Action
- Apply the latest Microsoft Office security update addressing CVE-2026-63529.
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-2026-63529
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-2026-635290.34% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 28% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-63529 | 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-2026-63529: Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information…nvd
Recent advisories for Microsoft Office Information
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.
- mediumCVE-2026-70328: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose infor…nvd · 2026-08-11
- mediumCVE-2026-70327: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose infor…nvd · 2026-08-11
- mediumCVE-2026-70325: Improper input validation in Microsoft Office PowerPoint allows an unauthorized attacker to di…nvd · 2026-08-11
- mediumCVE-2026-70323: Improper input validation in Microsoft Office allows an unauthorized attacker to disclose info…nvd · 2026-08-11
- mediumCVE-2026-70322: Improper input validation in Microsoft Office PowerPoint allows an unauthorized attacker to di…nvd · 2026-08-11
- mediumCVE-2026-70320: Improper input validation in Microsoft Office PowerPoint allows an unauthorized attacker to di…nvd · 2026-08-11
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