CVE-2018-8420
A remote code execution vulnerability exists when the Microsoft XML Core Services MSXML parser processes user input, aka "MS XML Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008,…
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 48.9%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
A remote code execution vulnerability exists when the Microsoft XML Core Services MSXML parser processes user input, aka "MS XML Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
- CVSS 3.0
- 8.8 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 48.90% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-611
- Affected
- microsoft/windows 10 · microsoft/windows 7 · microsoft/windows 8.1 · microsoft/windows server
- Source
- secure@microsoft.com
EPSS moved from 35.0% on 21 September 2026 to 48.9% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://www.securityfocus.com/bid/105259Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041627Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8420Patch, Vendor Advisory
- http://www.securityfocus.com/bid/105259Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041627Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8420Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.