Medium severity · published Sep 17, 2026
CVE-2026-54576
mport package installation has symlink TOCTOU in chown and chmod handling
5.8
CVSS
0.1%
EPSS
No
On KEV
Description
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MP
mport · MidnightBSD
< 2.7.8 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54576
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54576
github.com
https://github.com/MidnightBSD/mport/commit/4676ac05b1056b54a3d38d03ae8a478bf12c9abe
github.com
https://github.com/MidnightBSD/mport/pull/150
github.com
https://github.com/MidnightBSD/mport/releases/tag/2.7.8
github.com
https://github.com/MidnightBSD/mport/security/advisories/GHSA-23g3-7fv3-3ccf
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