CVE-2023-36456

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-07-06 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 06:06 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.8% in the next 30 days (EPSS).
• Severity: 8.3 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-07-06 19:15 UTC

Last modified

2026-06-17 06:06 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-436

Record status

Modified

Affected

• Goauthentik Authentik < 2023.4.3
• Goauthentik Authentik < 2023.5.5

Attack profile CVSS 3.1 · 8.3

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-36456.md and follow it. Check whether this project is affected by CVE-2023-36456. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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