CVE-2026-64617

Summary

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.

Affected Software

VendorProductVersion RangeStatus
EGORData::PubSub::Shared0 < 0.07affected

Weaknesses

  • CWE-732: CWE-732 Incorrect Permission Assignment for Critical Resource
  • CWE-59: CWE-59 Improper Link Resolution Before File Access

Workarounds

For deployments that cannot upgrade to 0.07, set a restrictive umask so the backing file is not world-readable and place it in a directory only the owning user can access.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References