CVE-2026-59143
Data::RoaringBitmap::Shared versions before 0.02 for Perl allow an out-of-bounds read via an unvalidated container offset and cardinality in rb_contains_locked. The attach-time validator rb_validate_header checks the header scalars and region layout against the file size, but does not validate the bucket contents it then trusts. rb_contains_locked forms a container pointer as pool + container_off * 8192 from a raw file-stored offset and then searches over a file-stored cardinality, neither bounded against the container pool capacity or the fixed 8192-byte slot size. A local peer that can write the backing file can leave the header valid while poisoning a bucket, so the next membership query dereferences a file-controlled wild pointer and scans a file-controlled count, reading adjacent memory or crashing the process.
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 : 6.3 MEDIUM
Vector: AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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.