-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-26:23.bsdinstall Security Advisory The FreeBSD Project Topic: Remote code execution via installer Wi-Fi access point scans Category: core Module: bsdinstall Announced: 2026-05-20 Credits: Austin Ralls Affects: All supported versions of FreeBSD. Corrected: 2026-05-20 19:36:43 UTC (stable/15, 15.0-STABLE) 2026-05-20 19:39:37 UTC (releng/15.0, 15.0-RELEASE-p9) 2026-05-20 19:38:03 UTC (stable/14, 14.4-STABLE) 2026-05-20 19:40:02 UTC (releng/14.4, 14.4-RELEASE-p5) 2026-05-20 19:40:40 UTC (releng/14.3, 14.3-RELEASE-p14) CVE Name: CVE-2026-45255 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background bsdinstall and bsdconfig are utilities that provide an interactive configuration mechanism for FreeBSD. Among other functionality, they can be used to configure FreeBSD to automatically join a Wi-Fi network. II. Problem Description When bsdinstall or bsdconfig are prompted to scan for nearby Wi-Fi networks, they build up a list of network names and use bsddialog(1) to prompt the user to select a network. This is implemented using a shell script, and the code which handled network names was not careful to prevent expansion by the shell. As a result, a suitably crafted network name can be used to execute commands via a subshell. III. Impact The problem can be exploited to execute code as root on the system running bsdinstall or bsdconfig. The attacker would need to create an access point with a specially crafted name and be within range of a Wi-Fi scan. Note that bsdinstall and bsdconfig are vulnerable as soon as the user prompts them to scan for nearby networks; they do not need to actually select the malicious network. IV. Workaround Avoid using bsdinstall or bsdconfig to scan for Wi-Fi networks, and instead configure Wi-Fi manually. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Perform one of the following: 1) To update your vulnerable system installed from base system packages: Systems running a 15.0-RELEASE version of FreeBSD on the amd64 or arm64 platforms, which were installed using base system packages, can be updated via the pkg(8) utility: # pkg upgrade -r FreeBSD-base 2) To update your vulnerable system installed from binary distribution sets: Systems running a RELEASE version of FreeBSD on the amd64 or arm64 platforms which were not installed using base system packages can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install 3) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 15.x] # fetch https://security.FreeBSD.org/patches/SA-26:23/bsdinstall-15.patch # fetch https://security.FreeBSD.org/patches/SA-26:23/bsdinstall-15.patch.asc # gpg --verify bsdinstall-15.patch.asc [FreeBSD 14.x] # fetch https://security.FreeBSD.org/patches/SA-26:23/bsdinstall-14.patch # fetch https://security.FreeBSD.org/patches/SA-26:23/bsdinstall-14.patch.asc # gpg --verify bsdinstall-14.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in . VI. Correction details This issue is corrected as of the corresponding Git commit hash in the following stable and release branches: Branch/path Hash Revision - ------------------------------------------------------------------------- stable/15/ 6f5674b97fd6 stable/15-n283646 releng/15.0/ b89f48ade920 releng/15.0-n281046 stable/14/ f15df0adbcd2 stable/14-n274170 releng/14.4/ dd50cc216e4d releng/14.4-n273709 releng/14.3/ 9cb0be8381f7 releng/14.3-n271509 - ------------------------------------------------------------------------- Run the following command to see which files were modified by a particular commit: # git show --stat Or visit the following URL, replacing NNNNNN with the hash: To determine the commit count in a working tree (for comparison against nNNNNNN in the table above), run: # git rev-list --count --first-parent HEAD VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQJPBAEBCgA5FiEEthUnfoEIffdcgYM7bljekB8AGu8FAmoOKH8bFIAAAAAABAAO bWFudTIsMi41KzEuMTIsMCwzAAoJEG5Y3pAfABrvTloP/0369bPHpZf0yt9C2VEk NyOeFq+58zQGrz+RRrXA6Vg2xNdaD3fcjpVzAoqzscuE2T7VqZkpi6cS+cbzEE40 NXX+d7qPgd5udqJR4gL8+90KWj7yQ9Wl0tnbV8wTLE6km/Dma+MXuDJrIqUl8Tsb q9hXGPfeymptS2vkR1Nj3VxEhDg0CCQz3bGD1sln7Oj63amX8HkHO9MwW8zHTyGj pcMqEF2sN3Zz0WyyaBf5XS9G0EP0BpicDIcF1NiwYbPi0rlA/nU/zjACfao7lEJk /XCq/iBKQsOiicvNGhoms/ku4YLNQv/L40FSJFNm8wmUsJD4fh6ll2+5Rm88666e gJUcBiLEzlKFogiel4JLqXMBaAZseV6Py8B+puAYh2eFCa/3aF6w2QppMj4jIHCL xEC/XUoBXN+34riiOCkPuSPqmgktvw7oZOBuk5DpV6qt7kdkInZ9i4HQnR13dhlF vLW88oyuO+2dUn+LiLaHi6f7gxkHcgyOOa/N60D95E9+d6Aop9otyMxNRFbSiQ7I x13B4j9ONtdAwL0uYJ+HPNHIfGTBHtpFzt62JfKdWqbSa5oVQrU5aq6wfMjMVupI sYCq+XNTN0MVr4iHowDPqwuEi0+RBoPOQPIXFZRfJr4uTdeim5dzX6fjfe95KIps 3nJWEVEXVF/FiFWL3C+Lk3Cv =Y3q0 -----END PGP SIGNATURE-----