CVE-2026-64613 EGOR CVE debrief

Who should care

Users of Data::Buffer::Shared versions before 0.05 for Perl should be aware of this vulnerability. The vulnerability allows local users to access sensitive information stored in the shared segment. Affected operators, platform administrators, vulnerability management teams, and security teams should review the official advisory and take necessary actions to mitigate the vulnerability.

Technical summary

The vulnerability is caused by the creation of a world-readable mmap backing file in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). The O_EXCL flag blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created with mode 0644 (world-readable). The O_NOFOLLOW flag is absent, allowing a symlink planted at the path to be followed when the segment is attached. This can lead to unauthorized access to sensitive information stored in the shared segment.

Defensive priority

High

Recommended defensive actions

• Update to version 0.05 or later of Data::Buffer::Shared
• Use a umask to restrict file permissions
• Implement additional access controls to restrict access to the shared segment
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-21T20:17:03.967Z and was last modified on 2026-07-22T16:21:53.517Z. The NVD entry is currently Deferred. Evidence is limited to public sources and may not reflect the full scope or impact of this vulnerability. Defenders should verify affected systems and review official advisories for specific guidance.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.