VulnerabilityAnalyzed
CVE-2026-55140
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
HIGH 7.8EPSS 0.47%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.47% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122
- Affected
- microsoft/365 apps · microsoft/microsoft 365 · microsoft/office 2016 · microsoft/office 2019 · microsoft/office 2021 · microsoft/office 2024
- Source
- secure@microsoft.com
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55140Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.