CVE-2026-71215
art-template's sub-template resolution logic (src/compile/adapter/resolve-filename.js), used by both the include() and extend() template directives, resolves the target file path via path.resolve(root, filename) with no check afterward that the result remains inside root. Because path.resolve() discards root entirely when filename is an absolute path, and does not block '../' traversal sequences, and the resolved path is passed directly to fs.readFileSync() in loader.js with its contents compiled and rendered, an application that lets a sub-template name be influenced by external input (e.g. a query parameter passed into {{include page}}) allows an attacker to read arbitrary files on disk that the Node process can access.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 7.5 HIGH
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.