CVE-2026-64613
Severity CVSS v4.0:
Pending analysis
Type:
CWE-59
Link Following
Publication date:
21/07/2026
Last modified:
23/07/2026
Description
Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.<br />
<br />
The segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached.<br />
<br />
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 symlink at the path redirects the open to another file.
Impact
Base Score 3.x
6.20
Severity 3.x
MEDIUM