VYPR
High severityNVD Advisory· Published Jan 30, 2024· Updated Jun 17, 2025

PKCE downgrade attack in Authentik

CVE-2024-23647

Description

Authentik is an open-source Identity Provider. There is a bug in our implementation of PKCE that allows an attacker to circumvent the protection that PKCE offers. PKCE adds the code_challenge parameter to the authorization request and adds the code_verifier parameter to the token request. Prior to 2023.8.7 and 2023.10.7, a downgrade scenario is possible: if the attacker removes the code_challenge parameter from the authorization request, authentik will not do the PKCE check. Because of this bug, an attacker can circumvent the protection PKCE offers, such as CSRF attacks and code injection attacks. Versions 2023.8.7 and 2023.10.7 fix the issue.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
goauthentik.ioGo
>= 2023.10.0, < 2023.10.72023.10.7
goauthentik.ioGo
< 2023.8.72023.8.7

Affected products

3

Patches

Vulnerability mechanics

References

4

News mentions

0

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