CVE-2026-54576: medium-severity vulnerability in MidnightBSD mport
mport package installation has symlink TOCTOU in chown and chmod handling
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.8epss 0.1%
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:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
Affected products
MidnightBSD · mportRelated CVEs — MidnightBSD mport
In the same product, most dangerous first.
CVE-2026-54582MEDIUMmport package installation can overwrite existing unmanaged or differently owned filesEPSS 0.6%CVE-2026-54585MEDIUMmport sample file handling can write outside the configured rootEPSS 0.5%CVE-2026-54583HIGHmport package bundle downloads allow unsafe destination filenamesEPSS 0.5%CVE-2026-54584MEDIUMmport trusts environment-controlled temporary directories in privileged metadata extractionEPSS 0.5%CVE-2026-54580HIGHmport index decompression can leave partial or corrupt index data after zstd failuresEPSS 0.3%CVE-2026-54581HIGHmport bootstrap index fetch can continue after hash verification failureEPSS 0.2%