CVE-2023-36456
Goauthentik Authentik ≤ 2023.4.3
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:LCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-36456 is a high-severity Interpretation Conflict (CWE-436) vulnerability in Goauthentik Authentik. Its CVSS base score is 8.3 (High).
Operationally, ranked in the top 45% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-40420
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.8.25 mandates a secure SDLC process with checkpoints, secure coding, testing and training; it does not stop differing interpretations of shared state or inputs between two products from arising or being exploited
A.8.26 only requires that security requirements (including resilience against injections or input controls) be identified and specified during development or acquisition; it does not itself enforce, implement or assure any mechanism that stops an interpretation conflict from being exploitable.
A.8.27 establishes and applies secure-by-design principles (defense-in-depth, least privilege, assume-breach, distrust-external-input, hardening, etc.) but does not stop two products from interpreting the same input or protocol step differently; the resulting state/conflict weakness can still be present and exploitable.
Secure coding standards can enforce canonical input handling and strict protocol compliance to avoid misinterpretation between products.
Security testing can detect and correct cases where one component misinterprets another’s state or messages.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-436, a class-level weakness, and none of its children carries one either.