GHSA-5qjq-69w6-fg57

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    GHSA-5qjq-69w6-fg57

    Published: 7 Jun 2021Last Modified: 8 Jul 2026

    Summary: XSS vulnerability with translator

    Details: Flarum's translation system allowed for string inputs to be converted into HTML DOM nodes when rendered. This change was made after v0.1.0-beta.16 (our last beta before v1.0.0) and was not noticed or documented. This allowed for any user to type malicious HTML markup within certain user input fields and have this execute on client browsers. The example which led to the discovery of this vulnerability was in the forum search box. Entering faux-malicious HTML markup, such as <script>alert('test')</script> resulted in an alert box appearing on the forum. This attack could also be modified to perform AJAX requests on behalf of a user, possibly deleting discussions, modifying their settings or profile, or even modifying settings on the Admin panel if the attack was targetted towards a privileged user. ### Impact All Flarum communities that run flarum v1.0.0 or v1.0.1 are impacted. ### Patches The vulnerability has been fixed and published as flarum/core v1.0.2. All communities running Flarum v1.0 have to upgrade as soon as possible to v1.0.2 using: ``` composer update --prefer-dist --no-dev -a -W ``` You can then confirm you run the latest version using: ``` composer show flarum/core ``` ### Workarounds __None.__ ### For more information For any questions or comments on this vulnerability please visit https://discuss.flarum.org/d/27558. For support questions create a discussion at https://discuss.flarum.org/t/support. A reminder that if you ever become aware of a security issue in Flarum, please report it to us privately by emailing [email protected], and we will address it promptly.

    Affected packages

    Package

    Name: flarum/core

    Purl: pkg:composer/flarum/core

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 1.0.0
    Fixed -1.0.2

    Affected versions

    v1.0.0
    v1.0.1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GHSA-5qjq-69w6-fg57 | CVE-DB