Critical severity · published Oct 14, 2025
CVE-2025-55315
ASP.NET Security Feature Bypass Vulnerability
9.9
CVSS
66.5%
EPSS
No
On KEV
Description
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)66.5% · higher than 99% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AC
ASP.NET Core 2.3 · Microsoft
2.3 before 2.3.6 · source: vendor
AC
ASP.NET Core 8.0 · Microsoft
8.0 before 8.0.21 · source: vendor
AC
ASP.NET Core 9.0 · Microsoft
9.0 before 9.0.10 · source: vendor
MV
Microsoft Visual Studio 2022 version 17.10 · Microsoft
17.10.0 before 17.10.20 · source: vendor
MV
Microsoft Visual Studio 2022 version 17.12 · Microsoft
17.12.0 before 17.12.13 · source: vendor
MV
Microsoft Visual Studio 2022 version 17.14 · Microsoft
17.14.0 before 17.14.17 · source: vendor
AC
Asp.net Core · Microsoft
2.3.0 before 2.3.6; 8.0.0 before 8.0.21; 9.0.0 before 9.0.10 · source: NVD
VS
Visual Studio 2022 · Microsoft
17.10.0 before 17.10.20; 17.12.10 before 17.12.13; 17.14.0 before 17.14.17 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55315
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-55315
Vendor Advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55315
andrewlock.net
https://andrewlock.net/understanding-the-worst-dotnet-vulnerability-request-smuggling-and-cve-2025-55315/
gist.github.com
https://gist.github.com/N3mes1s/d0897c13ca199e739ecc2b562f466040