CVE-2026-54586
UnratedPublished 2026-09-17 ยท last changed 2026-09-21
The fix
We hold no Microsoft remediation data for CVE-2026-54586, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.
What it is
mport is the MidnightBSD Package Manager. Prior to 2.7.8, the mport_fetch_index(), mport_fetch_bootstrap_index(), and mport_fetch_bundle() paths in libmport/fetch.c accepted non-HTTPS repository and package mirror URLs without a url_is_https() enforcement check. When a cleartext URL was configured or returned by mirror data, a network-positioned attacker could tamper with package index or package download traffic and compromise package selection or integrity. This issue is fixed in version 2.7.8.