CVE-2026-65064
Data::HashMap::Shared versions before 0.14 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW
- Published
- Updated
- Reserved
- Assigned by
- CPANSec
Description
Data::HashMap::Shared versions before 0.14 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW. The segment is created in shm_generic.h with open(path, O_RDWR | O_CREAT | O_CLOEXEC, 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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Low3.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Low3.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.14% · top 96% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.8.
Weakness
Affected products
- affected < 0.14
What to do
Solution: Upgrade to Data::HashMap::Shared 0.14 or later, which creates the backing file mode 0600 (owner-only) with O_EXCL and O_NOFOLLOW.
Workaround: For deployments that cannot upgrade to 0.14, set a restrictive umask so the backing file is not world-readable and place it in a directory only the owning user can access.
References (2)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-65064)Record last updated .