CVE-2026-65066: CWE-732 Incorrect Permission Assignment for Critical Resource in EGOR Data::RingBuffer::Shared
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.
AI Analysis
Technical Summary
The vulnerability in Data::RingBuffer::Shared (CVE-2026-65066) arises from the creation of a backing file with mode 0666 (resulting in 0644 after umask) and opening it without O_EXCL or O_NOFOLLOW. This leads to a world-readable file in shared directories, enabling local attackers to read inter-process communication data and perform pre-creation race or symlink redirection attacks. The issue is due to incorrect permission assignment (CWE-732) and improper handling of symbolic links (CWE-59).
Potential Impact
Local users on the system can read sensitive IPC payloads stored in the world-readable backing file. Additionally, attackers can exploit the absence of O_EXCL and O_NOFOLLOW to perform race conditions or redirect file opens via symlinks, potentially leading to unauthorized data access or manipulation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid running Data::RingBuffer::Shared in environments where untrusted local users have access to the shared directories used for the backing file. Consider manually restricting permissions on the backing file and ensuring secure file creation flags if possible.
CVE-2026-65066: CWE-732 Incorrect Permission Assignment for Critical Resource in EGOR Data::RingBuffer::Shared
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.
Affected software
pkg:github/Data-RingBuffer-SharedRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Data::RingBuffer::Shared (CVE-2026-65066) arises from the creation of a backing file with mode 0666 (resulting in 0644 after umask) and opening it without O_EXCL or O_NOFOLLOW. This leads to a world-readable file in shared directories, enabling local attackers to read inter-process communication data and perform pre-creation race or symlink redirection attacks. The issue is due to incorrect permission assignment (CWE-732) and improper handling of symbolic links (CWE-59).
Potential Impact
Local users on the system can read sensitive IPC payloads stored in the world-readable backing file. Additionally, attackers can exploit the absence of O_EXCL and O_NOFOLLOW to perform race conditions or redirect file opens via symlinks, potentially leading to unauthorized data access or manipulation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid running Data::RingBuffer::Shared in environments where untrusted local users have access to the shared directories used for the backing file. Consider manually restricting permissions on the backing file and ensuring secure file creation flags if possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- CPANSec
- Date Reserved
- 2026-07-21T15:29:37.116Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a5fcbb72a4a8d5989ac73bc
Added to database: 07/21/2026, 19:42:47 UTC
Last enriched: 07/21/2026, 19:51:50 UTC
Last updated: 07/21/2026, 20:46:08 UTC
Views: 5
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.