Description
Free of memory not on the heap in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Affected products
microsoft: 365 apps; microsoft: excel; microsoft: office; microsoft: office long term servicing channel
References1
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54899 Vendor Advisory
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 48 · as of 8 November 2026
- CWE
- CWE-590
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.