CVE-2026-65066
LOW
INFO
Priority: 0.01
BB Relevance:
33/100
Published: 2026-07-21
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Low Complexity
No Interaction
Scope Change
CVSS Vector Breakdown
AV:
Local
AC:
Low
PR:
Low
UI:
None
S:
Changed
C:
Low
I:
None
A:
None
Description
Data::RingBuffer::Shared versions before 0.04 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW. The segment is created in ring.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.