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Servers and applications

CVE-2024-23647

PKCE downgrade attack in authentik

Severity
High 8.8
Published
29 Jan 2024
Last changed
17 Jun 2026
Added to UpHeron
1 Nov 2026
Fixed in
2023.8.7, 2023.10.7
Also known as
GHSA-mrx3-gxjx-hjqj
Sources
NVD, Project advisories (GitHub)

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…

Affected software

SoftwareAffected versions
authentikServers and applications · cpe:a:goauthentik:authentik
  • Every version before 2023.8.7
  • From 2023.10.0 before 2023.10.7
authentikServers and applications · github:goauthentik/authentik
  • Every version before 2023.10.7
  • Every version before 2023.8.7

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2024-23647
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2024-23647
  • GitHub Advisory Database https://github.com/advisories/GHSA-mrx3-gxjx-hjqj
  • github.com https://github.com/goauthentik/authentik/security/advisories/GHSA-mrx3-gxjx-hjqj