CVE-2026-64614

Data::Deque::Shared versions before 0.06 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW

Published Jul 21, 2026 CVSS 3.1 · 3.8 Low EPSS < 1% KEV · Not listed
Description
Data::Deque::Shared versions before 0.06 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW.

The segment is created in deque.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.

Remediation

Vendor Solution

Upgrade to Data::Deque::Shared 0.06 or later, which creates the backing file mode 0600 (owner-only) with O_EXCL and O_NOFOLLOW.


Vendor Workaround

For deployments that cannot upgrade to 0.06, set a restrictive umask so the backing file is not world-readable and place it in a directory only the owning user can access.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Egor
Egor data::deque::shared
Vendors & Products Egor
Egor data::deque::shared
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 3.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Data::Deque::Shared versions before 0.06 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW. The segment is created in deque.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.
Title Data::Deque::Shared versions before 0.06 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW
Weaknesses CWE-59
CWE-732
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Jul 23, 2026, 12:40 PM
Reserved
Jul 20, 2026, 11:30 AM
Status
Deferred
Published
Jul 21, 2026, 8:17 PM
Modified
Oct 24, 2026, 7:10 PM