CVE-2026-116250 pgAdmin 4: Files opened in a storage directory follow a symbolic link, hard link or FIFO planted after the containment check

Description

In server mode pgAdmin 4 validates a path a user gives for a file in their storage directory with check_access_permission() and then opened it by name. Several places opened it with a plain open() or handed the path to a utility that opened it later: the servers.json export and import and the import file listing, and the files given to pg_dump, pg_dumpall, pg_restore and psql by Backup, Restore and Import/Export Data. A symbolic link swapped in at the file or at any parent directory between the check and the open redirected the operation outside the storage directory, so a file could be written, overwritten or read, or loaded into a table, as the operating-system account running pgAdmin. A hard link to an outside file, which O_NOFOLLOW does not detect, and a FIFO, which could hang a request, had the same effect. CVE-2026-86861 fixed this for the File Manager's save_file; these were the remaining paths. Exploitation requires creating such a link or FIFO inside the user's storage directory. pgAdmin offers no way to do so, and the per-user storage directories belong to the pgAdmin account, so this requires write access to the storage backend as a different operating-system user, for example a shared or network-mounted storage directory, and winning the race. The fix opens each file by walking down from the storage directory one component at a time with O_NOFOLLOW, accepting only a regular file with one link, and passes the utilities the open descriptor (/dev/fd/N) on Linux. Error messages no longer include the server path. This issue affects pgAdmin 4: before 9.19.

Exploitable avec un accès local à la machine, avec un compte ordinaire et sans action d’un utilisateur ; un attaquant peut compromettre gravement la confidentialité, l’intégrité ou la disponibilité.

Vecteur d’attaque

Local

Complexité

Élevée

Privilèges requis

Faibles

Interaction

Aucune

Portée

Inchangée

Confidentialité

Élevé

Intégrité

Élevé

Disponibilité

Faible

Produits et versions touchés