CVE-2017-8621
Microsoft Exchange Server 2010 SP3, Exchange Server 2013 SP3, Exchange Server 2013 CU16, and Exchange Server 2016 CU5 allows an open redirect vulnerability that could lead to spoofing, aka "Microsoft Exchange Open Redirect Vulnerability".
Does this matter?
Lower severity and a low EPSS score (3.17%). Track it; it rarely justifies an emergency change on its own.
Description
Microsoft Exchange Server 2010 SP3, Exchange Server 2013 SP3, Exchange Server 2013 CU16, and Exchange Server 2016 CU5 allows an open redirect vulnerability that could lead to spoofing, aka "Microsoft Exchange Open Redirect Vulnerability".
- CVSS 3.0
- 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 3.17% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- microsoft/exchange server
- Source
- secure@microsoft.com
EPSS moved from 4.4% on 21 September 2026 to 3.2% on 27 October 2026.
References
- http://www.securityfocus.com/bid/99533Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038852Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2017-8621Patch, Vendor Advisory
- http://www.securityfocus.com/bid/99533Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038852Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2017-8621Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.