cvedb.io
CVE-2026-41887
MEDIUM · CVSS 4.9
EPSS exploitation probability: 0%
Published 2026-05-08T17:16:30.890 · Last modified 2026-06-17T10:47:08.693

Summary

Flarum is open-source forum software. Prior to versions 1.8.16 and 2.0.0-rc.1, Flarum's patch for CVE-2023-27577 restricted the @import and data-uri() LESS features in the custom_less setting, but the same restriction was never applied to other settings registered as LESS config variables (for example theme_primary_color and theme_secondary_color, as well as any key registered via Extend\Settings::registerLessConfigVar()). Those values are interpolated verbatim into the LESS source at compile time, allowing an authenticated administrator to craft a theme-color value that injects an arbitrary @import directive into the compiled forum.css. Because the underlying LESS parser honours @import (inline) '<path>', an attacker can read arbitrary files reachable by the PHP process (local file inclus

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.