Flarum's logout Route allows open redirects

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS

• CVE-2024-21641: 1.07% estimated exploitation activity in the next 30 days; percentile 64.83 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The Flarum /logout route includes a redirect parameter that allows any third party to redirect users from a (trusted) domain of the Flarum installation to redirect to any link. Sample: example.com/logout?return=https://google.com. For logged-in users, the logout must be confirmed. Guests are immediately redirected. This could be used by spammers to redirect to a web address using a trusted domain of a running Flarum installation. Some ecosystem extensions modifying the logout route have already been affected. Sample: https://discuss.flarum.org/d/22229-premium-wordpress-integration/526 Patches The vulnerability has been fixed and published as flarum/core v1.8.5. All communities running Flarum should upgrade as soon as possible to v1.8.5 using: composer update --prefer-dist --no-dev -a -W You can then confirm you run the latest version using: composer show flarum/core Workarounds Some extensions modifying the logout route can remedy this issue if their implementation is safe. In…

Published by the source

5 Jan 2024, 20:53 UTC

Last modified by the source

17 Jan 2025, 18:15 UTC

Source last checked

26 Oct 2026, 14:29 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-733r-8xcp-w9mr

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# Patch Next advisory brief: CVE-2024-21641

Advisory: Flarum's logout Route allows open redirects
IDs: CVE-2024-21641, GHSA-733r-8xcp-w9mr
Record: https://patchnext.com/advisories/cve-2024-21641 (revision 1, source checked 26 Oct 2026, 14:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: flarum/framework 1.8.5; flarum/core 1.8.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist flarum/framework: affected < 1.8.5; fixed in 1.8.5
- Packagist flarum/core: affected < 1.8.5; fixed in 1.8.5

## Suggested inspection (read-only)
- Packagist flarum/framework: check the installed version with your package manager.
- Packagist flarum/core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on flarum/framework, flarum/core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-733r-8xcp-w9mr (GitHub-reviewed advisory GHSA-733r-8xcp-w9mr lists affected ranges: Packagist flarum/core >=0 =0 <1.8.5)

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