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CVE-2026-64613 EGOR CVE debrief

CVE-2026-64613 is a vulnerability in Data::Buffer::Shared versions before 0.05 for Perl. The package creates a world-readable mmap backing file and opens it without the O_NOFOLLOW flag. This allows any local user to read the IPC payloads stored in the shared segment. A pre-planted symlink at the path can redirect the open to another file. The vulnerability has a high defensive priority due to its potential for local privilege escalation and data exposure.

Vendor
EGOR
Product
Data::Buffer::Shared
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-21
Original CVE updated
2026-07-22
Advisory published
2026-07-21
Advisory updated
2026-07-22

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.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-21T20:17:03.967Z and has not been modified since then. The NVD entry is currently Deferred.