CVE-2026-41887 Flarum: Path traversal in LESS parser via theme color settings (incomplete fix for CVE-2023-27577)

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 customless setting, but the same restriction was never applied to other settings registered as LESS config variables for exampl...

Flarum: Path traversal in LESS parser via theme color settings (incomplete fix for CVE-2023-27577)

Summary Flarum's patch for CVE-2023-27577 restricted the @import and data-uri LESS features in the customless setting, but the same restriction was never applied to other settings registered as LESS config variables for example themeprimarycolor and themesecondarycolor, as well as any key...

CVE-2023-27577 Path Traversal Vulnerability in `LESS` Parser allows reading of sensitive server files in flarum

flarum is a forum software package for building communities. In versions prior to 1.7.0 an admin account which has already been compromised by an attacker may use a vulnerability in the LESS parser which can be exploited to read sensitive files on the server through the use of path traversal...

CVE-2023-27577 Path Traversal Vulnerability in `LESS` Parser allows reading of sensitive server files in flarum

flarum is a forum software package for building communities. In versions prior to 1.7.0 an admin account which has already been compromised by an attacker may use a vulnerability in the LESS parser which can be exploited to read sensitive files on the server through the use of path traversal...

CVE-2023-27577

Summary : CVE-2023-27577 affects flarum prior to 1.7.0. A compromised admin account can exploit a flaw in the LESS parser to perform path traversal and read sensitive server files (e.g., /etc/passwd) by supplying an absolute path in the custom LESS setting. The vulnerability’s impact depends on t...