[NEW] [high] Microsoft Excel (2016), Office (2019, 2021 and 2024) and 365 Apps: Vulnerability allows code execution

highCVE-2026-62870

A remote anonymous attacker can exploit a vulnerability in Microsoft Excel 2016, Microsoft Office 2024, Microsoft Office 2021, Microsoft 365 Apps Enterprise and Microsoft Office 2019 to execute arbitrary code.

CSIRTS triage

vendor: Microsoft product: Excel and Office Remote code executionaffected: Excel 2016, Office 2019, Office 2021, Office 2024, 365 Apps

What: A remote attacker can execute arbitrary code in Microsoft Excel and Office products through an unauthenticated attack.
Who is affected: Organizations and users running Microsoft Excel 2016, Office 2019, 2021, 2024, and 365 Apps.
Urgency: Critical priority; unauthenticated remote code execution in widely-used productivity software requires emergency patching.
Action: Apply Microsoft security updates for Excel and Office products addressing CVE-2026-62870 immediately.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Excel and Office

Get an email when a new Excel and Office advisory drops — max one per day, one-click unsubscribe.

Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: high
Published: 2026-08-04
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2625

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-2026-628700.84% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 54% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-62870	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Microsoft Excel

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-2026-62870: Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code over …nvd · 2026-08-04
highCVE-2026-56156: Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execut…nvd · 2026-07-14
highCVE-2026-55949: Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to exe…nvd · 2026-07-14
highCVE-2026-55947: Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execut…nvd · 2026-07-14
mediumCVE-2026-55898: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose infor…nvd · 2026-07-14
highCVE-2026-55141: Stack-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execu…nvd · 2026-07-14