CVE-2026-42849
Stored XSS in Authentik Identity Provider
Publication date: 2026-06-02
Last updated on: 2026-06-02
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| goauthentik | authentik | to 2026.2.3 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in authentik, an open-source identity provider, due to the implementation of stages in the Simple Flow Executor (SFE) designed to improve compatibility with legacy browsers. Specifically, it was possible to exploit a cross-site scripting (XSS) vulnerability in the AutosubmitStage component before versions 2025.12.5 and 2026.2.3, which have since patched the issue.
How can this vulnerability impact me? :
The vulnerability allows an attacker to perform a cross-site scripting (XSS) attack, which can lead to severe impacts such as complete compromise of confidentiality and integrity of data. According to the CVSS score of 9.3, this vulnerability can be exploited remotely without privileges and requires user interaction, potentially allowing attackers to execute malicious scripts in the context of the affected application, leading to data theft or manipulation.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade authentik to version 2025.12.5 or later, or version 2026.2.3 or later, where the issue has been patched.