Pgadmin: >> Pgadmin 4 >> 9.16 Security Vulnerabilities
The fix for CVE-2026-12045 in pgAdmin 4 9.16 required the LLM-supplied query passed to the AI Assistant's execute_sql_query tool to parse, via sqlparse, as exactly one non-transaction-control statement before running it inside a BEGIN TRANSACTION READ ONLY wrapper. sqlparse's string-literal lexing can disagree with PostgreSQL's own parser: under standard_conforming_strings = on (PostgreSQL's default since 9.1), a backslash immediately before a quote is an ordinary character to PostgreSQL, but sqlparse treats it as escaping the quote. A payload such as SELECT '\';COMMIT;CREATE TABLE pwn(x int);SELECT 1 --' therefore parses as a single SELECT to sqlparse's validator, while PostgreSQL executes it as four statements: the smuggled COMMIT ends the wrapping read-only transaction, and the trailing ROLLBACK becomes a no-op. This reintroduces the same write/RCE bypass CVE-2026-12045 was meant to close, reachable via the same indirect prompt-injection delivery (an attacker plants the payload in any object the AI Assistant may read; the LLM emits it as a tool call).
An initial candidate fix ran the query with psycopg's execute(..., prepare=True), intending to force PostgreSQL's own Parse step (extended query protocol) to reject multi-statement text regardless of sqlparse's classification. This candidate fix does not work as submitted: psycopg3's PrepareManager silently ignores the prepare argument whenever the connection's prepare_threshold is None, which is pgAdmin's default for every server connection (the per-server "Prepare threshold" field is blank unless an administrator explicitly sets it) -- psycopg3 falls back to the simple query protocol, the same multi-statement-capable path the bypass exploits, so the candidate fix closes nothing on any real-world default configuration.
The corrected fix sets conn.prepare_threshold = 0 directly on the dedicated, single-use read-only connection the AI Assistant tool opens, structurally forcing the extended query protocol independent of any server-level configuration. Verified against a live PostgreSQL 18 instance: the payload executes successfully under the prepare_threshold=None (default) behavior, and is rejected with "cannot insert multiple commands into a prepared statement" once prepare_threshold=0 is set on that connection.
This issue affects pgAdmin 4: from 9.13 before 9.17.
CVSS Score
9.4
EPSS Score
0.005
Published
2026-07-31
The fix for CVE-2026-12044 in pgAdmin 4 9.16 hardened qtLiteral and switched sixteen COMMENT ON / pgstattuple / pgstatindex templates to it, but missed several sinks that had been placed in test_sql_string_literal_lint.py's ALLOWLIST on the incorrect assumption that schema, table, publication, and subscription names sourced from pg_catalog via the browser tree could never contain an apostrophe. PostgreSQL permits arbitrary characters in quoted identifiers, so a low-privileged user able to CREATE TABLE, CREATE PUBLICATION, or CREATE SUBSCRIPTION can plant an apostrophe'd object name that breaks out of the unescaped '{{ name }}' template interpolation the moment any user (including a higher-privileged one) opens that object's Statistics or Dependencies tab, allowing arbitrary SQL statement injection in the viewing user's database session.
Affected sinks: the Index Statistics query for all-indexes listing (coll_stats.sql, both the 16_plus and default PostgreSQL-version template variants -- distinct from the single-index stats.sql path already fixed in CVE-2026-12044), and the publication and subscription dependencies.sql / get_position.sql templates (both the pg and ppas/EPAS dialect variants for publications).
Fix switches all of these templates to qtLiteral(conn) for name interpolation, and updates publications/__init__.py and subscriptions/__init__.py to pass conn=self.conn into the dependencies.sql render_template call so the qtLiteral filter has a connection to quote against. The corresponding ALLOWLIST entries in test_sql_string_literal_lint.py are removed now that these sinks are properly escaped rather than merely assumed safe. A behavioral regression test renders each fixed template with a stacked-statement apostrophe payload and asserts both that the object name appears exactly as qtLiteral-escaped and that the rendered SQL parses as exactly one statement, verifying the assertion genuinely fails against the pre-patch raw-interpolation form.
This issue affects pgAdmin 4: the Index Statistics sink from 1.0, and the Publications/Subscriptions sinks from 5.0, both before 9.17.
CVSS Score
8.7
EPSS Score
0.006
Published
2026-07-31
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