CVE-2023-36456
highpriority · track · 29EPSS 0.008 · 56 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.7–8.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- BIT-authentik-2023-36456Authentik lacks Proxy IP headers validation2026-04-16vendor · osvUS
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.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (16)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-36456/cnnvd
- https://github.com/goauthentik/authentik/commit/15026748d19d490eb2baf9a9566ead4f805f7dffcnnvd
- https://github.com/goauthentik/authentik/commit/c07a48a3eccbd7b23026f72136d3392bbc6f795acnnvd
- https://github.com/goauthentik/authentik/security/advisories/GHSA-cmxp-jcw7-jjjvcnnvd
- https://goauthentik.io/docs/releases/2023.4#fixed-in-202343cnnvd
- https://goauthentik.io/docs/releases/2023.5#fixed-in-202355cnnvd
- https://github.com/goauthentik/authentik/commit/15026748d19d490eb2baf9a9566ead4f805f7dffenisa_euvd
- https://github.com/goauthentik/authentik/commit/c07a48a3eccbd7b23026f72136d3392bbc6f795aenisa_euvd
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