CVE-2020-0645
A tampering vulnerability exists when Microsoft IIS Server improperly handles malformed request headers, aka 'Microsoft IIS Server Tampering Vulnerability'.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.90%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A tampering vulnerability exists when Microsoft IIS Server improperly handles malformed request headers, aka 'Microsoft IIS Server Tampering Vulnerability'.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 3.90% probability · 90th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- microsoft/windows 10 · microsoft/windows 7 · microsoft/windows 8.1 · microsoft/windows rt 8.1 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019
- Source
- secure@microsoft.com
EPSS 3.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0645Patch, Vendor Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0645Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.