VulnerabilityModified

CVE-2018-8421

CRITICAL 9.8EPSS 29.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 29.1%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

Description

A remote code execution vulnerability exists when Microsoft .NET Framework processes untrusted input, aka ".NET Framework Remote Code Execution Vulnerability." This affects Microsoft .NET Framework 4.6, Microsoft .NET Framework 3.5, Microsoft .NET Framework 4.7/4.7.1/4.7.2, Microsoft .NET Framework 3.0, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2, Microsoft .NET Framework 4.5.2, Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.1/4.7.2, Microsoft .NET Framework 4.7.1/4.7.2, Microsoft .NET Framework 4.7.2, Microsoft .NET Framework 2.0.

CVSS 3.0: 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 29.07% probability · 98th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-20
Affected: microsoft/.net framework
Source: secure@microsoft.com

EPSS trend

EPSS moved from 26.4% on 21 September 2026 to 29.1% 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/105222Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041636Third Party Advisory, VDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8421Patch, Vendor Advisory
http://www.securityfocus.com/bid/105222Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041636Third Party Advisory, VDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8421Patch, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.