CVE-2025-64521Network attack vector

OAuth token issuance via inactive-account lookup

Published Nov 19, 2025 · Updated Nov 19, 2025

Authentication bypass in authentik 2025.8.4 and earlier and 2025.10.1 and earlier allows remote authenticated users to obtain OAuth tokens. The OAuth token endpoint's __post_init_client_credentials_creds method looked up a username without filtering User.is_active before validating its token. Exploitation requires valid service-account credentials and access to the provider's client-credentials flow; assigned permissions and federation policies still constrain access.

CVSS severity4.8
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in authentik 2025.8.4 and earlier and 2025.10.1 and earlier allows remote authenticated users to obtain OAuth tokens. The OAuth token endpoint's __post_init_client_credentials_creds method looked up a username without filtering User.is_active before validating its token. Exploitation requires valid service-account credentials and access to the provider's client-credentials flow; assigned permissions and federation policies still constrain access.

The record

CVE
CVE-2025-64521
Published
Nov 19, 2025
Updated
Nov 19, 2025
Vendor
Authentik Security Inc.
Product
authentik
Classifications
CWE-286, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2025.10.2
  2. Affected versionversion=< 2025.8.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Authentik Security Inc. · authentikversion=< 2025.10.2; version=< 2025.8.5

Published CVSS scores

4.8GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-286Incorrect User Management
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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