{"id":"CVE-2026-64613","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64613","generatedAt":"2026-10-28T02:22:48.500Z","title":"Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.","description":"Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.\n\nThe segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached.\n\nA \"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 symlink at the path redirects the open to another file.","published":"2026-07-21T20:17:04.000Z","lastModified":"2026-10-24T19:10:00.000Z","status":"Deferred","sourceIdentifier":"9b29abf9-4ab0-4765-b253-1875cd9b441e","cvss":{"version":"3.1","score":6.2,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-59","CWE-732"],"affected":[],"epss":{"score":0.00176,"percentile":0.07068,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.18%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/changes","source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/diff/EGOR/Data-Buffer-Shared-0.04#buf_generic.h","source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64613","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}