# CVE-2025-27794: Flarum Vulnerable to Session Hijacking via Authoritative Subdomain Cookie Overwrite

Source: https://junglewise.ai/threats/cve-2025-27794-flarum-vulnerable-to-session-hijacking-via-authoritative  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-03-12  
License: CC BY 4.0 with a link back

CVE-2025-27794 · Severity: low · CVSS 3.1 · Published 2025-03-12

Flarum Vulnerable to Session Hijacking via Authoritative Subdomain Cookie Overwrite

Technologies: [flarum/core (Packagist)](https://junglewise.ai/threats/technologies/flarum-core), [flarum/framework (Packagist)](https://junglewise.ai/threats/technologies/flarum-framework). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2025-27794 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-27794 being exploited in the wild.

**How severe is CVE-2025-27794?** Low severity, with a CVSS score of 3.1, published 12 March 2025.

**Which products and versions are affected?** flarum/core (Packagist) ECOSYSTEM:introduced=0,fixed=1.8.10; flarum/framework (Packagist) ECOSYSTEM:introduced=0,fixed=1.8.10.

**Is there a fix for CVE-2025-27794?** Yes. flarum/core (Packagist): upgrade to 1.8.10 or later; flarum/framework (Packagist): upgrade to 1.8.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-27794?** Check whether you run flarum/core (Packagist) or flarum/framework (Packagist) 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

- flarum/core (Packagist): upgrade to 1.8.10 or later

  ```sh
  composer require flarum/core:^1.8.10
  ```

- flarum/framework (Packagist): upgrade to 1.8.10 or later

  ```sh
  composer require flarum/framework:^1.8.10
  ```


## Affected products

- flarum/core (Packagist) ECOSYSTEM:introduced=0,fixed=1.8.10
- flarum/framework (Packagist) ECOSYSTEM:introduced=0,fixed=1.8.10

## Identifiers

- CVE-2025-27794
- GHSA-hg9j-64wp-m9px

## Related threats

- [Flarum LFI and SSRF via LESS theme settings injection](https://junglewise.ai/threats/cve-2026-41887-flarum-path-traversal-and-ssrf-in-less-parser-theme-settings)
- [Flarum's logout Route allows open redirects](https://junglewise.ai/threats/cve-2024-21641-flarum-s-logout-route-allows-open-redirects)
- [Flarum vulnerable to LFI and Blind SSRF via Avatar upload](https://junglewise.ai/threats/cve-2023-40033-flarum-vulnerable-to-lfi-and-blind-ssrf-via-avatar-upload)
- [Path Traversal Vulnerability in `LESS` Parser allows reading of sensitive server files](https://junglewise.ai/threats/cve-2023-27577-path-traversal-vulnerability-in-less-parser-allows-reading-of)
- [Any Flarum user including unactivated can reply in public discussions whose first post was permanently deleted](https://junglewise.ai/threats/cve-2023-22489-any-flarum-user-including-unactivated-can-reply-in-public)