CVE-2026-65065 Information disclosure in Data::RoaringBitmap::Shared
Local attackers can read shared memory segments or hijack file creation due to insecure permissions and missing symlink protections in the Perl library.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-65065?
CVE-2026-65065 is a medium-severity vulnerability in EGOR Data::RoaringBitmap::Shared, published on 21 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Data::RoaringBitmap::Shared versions before 0.02 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW.
The segment is created in roaring.h with open(path, O_RDWR|O_CREAT, 0666). The mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable). O_NOFOLLOW is absent, so a symlink planted at the path is followed, and O_EXCL is absent, so the open silently uses a pre-planted file instead of failing.
A "Shared" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted file or symlink at the path lets a local attacker win a pre-creation race or redirect the open.
Which versions are affected by CVE-2026-65065?
How do I fix CVE-2026-65065?
No fix has been published for CVE-2026-65065 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-65065 being exploited?
There is no known exploitation of CVE-2026-65065 in the wild and no public exploit code.
Sources
Also known as GHSA-g774-r9mw-4c65.