CPANSA-Data-PubSub-Shared-2026-64617: Data-PubSub-Shared vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-07-21T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-07-21T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 3.8 | Severity | Low |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
Data::PubSub::Shared versions before 0.07 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW.
The segment is created in pubsub.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.
Vulnerabilities
CVE-2026-64617
Vulnerability DescriptionData::PubSub::Shared versions before 0.07 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW.
The segment is created in pubsub.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.
| Weakness | CWE-59 : Improper Link Resolution Before File Access ('Link Following') |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Data-PubSub-Shared less than 0.07 |
|
Fixed
- Data-PubSub-Shared greater than or equal 0.07
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Data-PubSub-Shared-2026-64617 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-data-pubsub-shared-2026-64617.json - https://metacpan.org/release/EGOR/Data-PubSub-Shared-0.07/changes external
https://metacpan.org/release/EGOR/Data-PubSub-Shared-0.07/changes - https://metacpan.org/release/EGOR/Data-PubSub-Shared-0.07/diff/EGOR/Data-PubSub-Shared-0.06#pubsub.h external
https://metacpan.org/release/EGOR/Data-PubSub-Shared-0.07/diff/EGOR/Data-PubSub-Shared-0.06#pubsub.h - CVE-2026-64617 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-64617
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Tue Jul 21 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/