Medium 5.8Published Sep 17, 2026

CVE-2026-54576mport package installation has symlink TOCTOU in chown and chmod handling

Updated under an hour ago (2026-10-19 06:10 UTC)

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It affects MidnightBSD mport. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for MidnightBSD mport

Exploited in the last 30 days

mport is the MidnightBSD Package Manager. Prior to 2.7.8, do_actual_install() in libmport/bundle_read_install_pkg.c used path-based lstat(), chown(), stat(), and chmod() operations while installing package files. A local attacker with write access to a target directory could replace a checked file with a symlink before privileged ownership or mode changes were applied, redirecting those changes to an attacker-selected path and compromising filesystem integrity or permissions. This issue is fixed in version 2.7.8.

CVSS: 5.8 MEDIUM (v4.0, CNA)CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
Weakness (CWE): CWE-59, CWE-367
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

MidnightBSD mport midnightbsd:mport (from the name)	before 2.7.8	CNA record

References

https://github.com/MidnightBSD/mport/security/advisories/GHSA-23g3-7fv3-3ccfx-refsource-confirm
https://github.com/MidnightBSD/mport/pull/150x-refsource-misc
https://github.com/MidnightBSD/mport/commit/4676ac05b1056b54a3d38d03ae8a478bf12c9abex-refsource-misc
https://github.com/MidnightBSD/mport/releases/tag/2.7.8x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.