Every CVE Search/ Get API key

CVE-2025-46814

FastAPI Guard Remote Header Injection via X-Forwarded-For Manipulation

3.4 LowFix available

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
Low
Integrity
None
Availability
None

Exploit likelihood

0.34%Up 0.3 points since May 7, 2025
90%50%10%1%

What each source reports

CVE List Score used 3.4

FastAPI Guard Remote Header Injection via X-Forwarded-For Manipulation

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Record
CVE-2025-46814
CVSS 3.1
3.4 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
Weakness
CWE-74
Updated
2026-11-02
EUVDEUVD-2025-13598 3.4

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Record
EUVD-2025-13598
CVSS 3.1
3.4 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
Updated
2026-11-02
NVD 3.4

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Record
CVE-2025-46814
CVSS 3.1
3.4 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-74
Updated
2026-11-02
OSV 3.4

FastAPI Guard Remote Header Injection via X-Forwarded-For Manipulation

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Record
CVE-2025-46814
CVSS 3.1
3.4 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
Weakness
CWE-74
Updated
2026-11-02
OSVPYSEC-2025-242 7.5

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

Record
PYSEC-2025-242
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
fastapi-guard
PyPI
before 2.0.0, plus listed versions
0.1.00.2.00.3.20.3.30.3.4
Show 9 moreShow less
0.4.01.0.01.1.01.2.01.2.11.2.21.3.21.4.01.5.0
2.0.0

History

History
RecordedChangedSources
first indexedCVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-46814 is a low vulnerability (CVSS 3.4) in Fastapi-guard Fastapi Guard, published May 6, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. Fixed in fastapi-guard 2.0.0.

References

MoveEnter Open