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CVE-2026-64613 Detail

Description

Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW. 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. 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.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
CPANSec
CPANSec

Weakness Enumeration

CWE-ID CWE Name Source
CWE-59 Improper Link Resolution Before File Access ('Link Following') CPANSec  
CWE-732 Incorrect Permission Assignment for Critical Resource CPANSec  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-64613
NVD Published Date:
07/21/2026
NVD Last Modified:
07/21/2026
Source:
CPANSec