CVE-2023-36456
Authentik lacks Proxy IP headers validation
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
8.3
Authentik lacks Proxy IP headers validation
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
- Record
CVE-2023-36456- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Weakness
- CWE-436
- Updated
- 2026-11-02
EUVDEUVD-2023-40420
8.3
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
- Record
EUVD-2023-40420- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Updated
- 2026-11-03
NVD
8.3
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
- Record
CVE-2023-36456- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-436
- Updated
- 2026-11-02
OSV
8.3
Authentik lacks Proxy IP headers validation
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
- Record
CVE-2023-36456- CVSS 3.1
- 8.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Weakness
- CWE-436
- Updated
- 2026-11-02
OSVBIT-authentik-2023-36456 No score
Authentik lacks Proxy IP headers validation
authentik is an open-source Identity Provider. Prior to versions 2023.4.3 and 2023.5.5, authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code. Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.
This poses a possible security risk when someone has flows or policies that check the user's IP address, e.g. when they want to ignore the user's 2 factor authentication when the user is connected to the company network. A second security risk is that the IP addresses in the logfiles and user sessions are not reliable anymore. Anybody can spoof this address and one cannot verify that the user has logged in from the IP address that is in their account's log. A third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.
Versions 2023.4.3 and 2023.5.5 contain a patch for this issue.
- Record
BIT-authentik-2023-36456- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
authentikBitnami |
before 2023.4.3, 2023.5.0 up to 2023.5.5 | 2023.4.32023.5.5 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-36456 is a high vulnerability (CVSS 8.3) in Goauthentik Authentik, published July 6, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.79%, the 56th percentile. Fixed in authentik 2023.4.3.
References
github.com/goauthentik/authentik/security/advisories/GHSA-cmxp-jcw7-jjjv
github.com/goauthentik/authentik/commit/15026748d19d490eb2baf9a9566ead4f805f7dff
github.com/goauthentik/authentik/commit/c07a48a3eccbd7b23026f72136d3392bbc6f795a
goauthentik.io/docs/releases/2023.4
goauthentik.io/docs/releases/2023.5
nvd.nist.gov/vuln/detail/CVE-2023-36456
github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36456.json