{"id":"CVE-2026-17347","summary":"pgAdmin 4: OS command injection in MASTER_PASSWORD_HOOK via untrusted username substitution","details":"The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an administrator configure an external command that returns a per-user encryption key, with %u in the configured string replaced by the current user's name. The previous implementation substituted the username directly into the command string and executed the result with subprocess.Popen(..., shell=True). Because the username can originate from an external authentication source (OAuth/OIDC claims, Kerberos, webserver auth) rather than a value pgAdmin fully controls, a username containing shell metacharacters (';', '$()', backticks, pipes, '&&', newlines) allowed an authenticated user to execute arbitrary commands as the pgAdmin service account in any deployment where the configured hook string uses %u.\n\nFix tokenises the trusted, administrator-configured hook string into an argument vector first (using shlex in POSIX-quoting mode, with backslash-escaping disabled so Windows-style paths are not mis-parsed), substitutes the untrusted username into the individual argv elements, and executes with shell=False. The username is therefore always confined to a single argv element; any shell metacharacters it contains are inert. Administrators whose MASTER_PASSWORD_HOOK previously relied on shell features (pipes, redirection, environment-variable expansion, globbing) within the hook string itself must move that logic into the invoked script, since it is no longer interpreted by a shell.\n\nThis issue affects pgAdmin 4: from 7.2 before 9.17.","modified":"2026-08-02T03:47:19.700078274Z","published":"2026-07-31T15:59:16.588Z","database_specific":{"cna_assigner":"PostgreSQL","cwe_ids":["CWE-78","CWE-88"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/17xxx/CVE-2026-17347.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"7.2"},{"fixed":"9.17"}]},{"extracted_events":[{"introduced":"7.2"},{"fixed":"9.17"}],"source":"DESCRIPTION"}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/17xxx/CVE-2026-17347.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-17347"},{"type":"REPORT","url":"https://github.com/pgadmin-org/pgadmin4/issues/10191"},{"type":"FIX","url":"https://github.com/pgadmin-org/pgadmin4/commit/e7a85767314e7b0fe0b35fe80b9c1af38f48dff6"},{"type":"FIX","url":"https://github.com/pgadmin-org/pgadmin4/commit/ea7e798aac27174d2bacee1d6e136bed76a95e23"},{"type":"PACKAGE","url":"https://github.com/pgadmin-org/pgadmin4"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/pgadmin-org/pgadmin4","events":[{"introduced":"0"},{"fixed":"e7a85767314e7b0fe0b35fe80b9c1af38f48dff6"},{"fixed":"ea7e798aac27174d2bacee1d6e136bed76a95e23"}],"database_specific":{"source":"REFERENCES"}}],"versions":["REL-9_16","REL-9_15","REL-9_14","REL-9_13","REL-9_12","REL-9_11","REL-9_10","REL-9_9","REL-9_8","REL-9_7","REL-9_6","REL-9_5","REL-9_4","REL-9_3","REL-9_2","REL-9_1","REL-9_0","REL-8_14","REL-8_13","REL-8_12","REL-8_11","REL-8_10","REL-8_9","REL-8_8","REL-8_7","REL-8_6","REL-8_5","REL-8_4","REL-8_3","REL-8_2","REL-8_1","REL-8_0","REL-7_8","REL-7_7","REL-7_6","REL-7_5","REL-7_4","REL-7_3","REL-7_2","REL-7_1","REL-7_0","REL-6_21","REL-6_20","REL-6_19","REL-6_18","REL-6_17","REL-6_16","REL-6_15","REL-6_14","REL-6_13","REL-6_12","REL-6_11","REL-6_10","REL-6_9","REL-6_8","REL-6_7","REL-6_6","REL-6_5","REL-6_4","REL-6_3","REL-6_2","REL-6_1","REL-6_0","REL-5_7","REL-5_6","REL-5_5","REL-5_4","REL-5_3","REL-5_2","REL-5_1","REL-5_0","REL-4_30","REL-4_29","REL-4_28","REL-4_27","REL-4_26","REL-4_25","REL-4_24","REL-4_23","REL-4_22","REL-4_21","REL-4_20","REL-4_19","REL-4_18","REL-4_17","REL-4_16","REL-4_15","REL-4_14","REL-4_13","REL-4_12","REL-4_11","REL-4_10","REL-4_9","REL-4_8","REL-4_7","REL-4_6","REL-4_5","REL-4_4","REL-4_3","REL-4_2","REL-4_1","REL-4_0","REL-3_6","REL-3_5","REL-3_4","REL-3_3","REL-3_2","REL-3_1","REL-3_0","REL-2_1","REL-2_0","REL-2_0-RC2","REL-2_0-RC1","REL-1_6","REL-1_5","REL-1_4","REL-1_3","REL-1_2","REL-1_1","REL-1_0","REL-1_0-RC1","REL-1_0-BETA4","REL-1_0-BETA3","REL-1_0-BETA2","REL-1_0-BETA1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-17347.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}