# CVE-2021-29456: Authelia allows open redirects on the logout endpoint

Source: https://junglewise.ai/threats/cve-2021-29456-authelia-allows-open-redirects-on-the-logout-endpoint  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-03-16  
License: CC BY 4.0 with a link back

CVE-2021-29456 · Severity: low · CVSS 3.1 · Published 2023-03-16

Authelia allows open redirects on the logout endpoint

Technologies: [github.com/authelia/authelia/v4 (Go)](https://junglewise.ai/threats/technologies/github-com-authelia-authelia-v4). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2021-29456 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-29456 being exploited in the wild.

**How severe is CVE-2021-29456?** Low severity, with a CVSS score of 3.1, published 16 March 2023.

**Which products and versions are affected?** github.com/authelia/authelia/v4 (Go) SEMVER:introduced=0,fixed=4.28.0.

**Is there a fix for CVE-2021-29456?** Yes. github.com/authelia/authelia/v4 (Go): upgrade to 4.28.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-29456?** Check whether you run github.com/authelia/authelia/v4 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/authelia/authelia/v4 (Go): upgrade to 4.28.0 or later

  ```sh
  go get github.com/authelia/authelia/v4@v4.28.0
  ```


## Affected products

- github.com/authelia/authelia/v4 (Go) SEMVER:introduced=0,fixed=4.28.0

## Identifiers

- CVE-2021-29456
- GHSA-36f2-fcrx-fp4j

## Related threats

- [Authelia incorrect authorization via improper domain canonicalization](https://junglewise.ai/threats/cve-2026-48794-authelia-incorrect-authorization-via-improper-domain)
- [Authelia improper username canonicalization in Basic Auth](https://junglewise.ai/threats/cve-2026-47203-authelia-improper-username-canonicalization-in-basic-auth)
- [Authelia: Improper Neutralization of Input During Web Page Generation Leads to Potential Cross-site Scripting](https://junglewise.ai/threats/cve-2026-33525-authelia-improper-neutralization-of-input-during-web-page)
- [Authelia applies regulation separately to Username-based logins to Email-based logins](https://junglewise.ai/threats/cve-2025-24806-authelia-applies-regulation-separately-to-username-based-logins)
- [GO-2024-2744 - Access control change may take longer than expected in github.com/authelia/authelia/v4](https://junglewise.ai/threats/go-2024-2744-access-control-change-may-take-longer-than-expected-in-55e6475c)