---
id: CVE-2026-17351
title: >-
  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
  TR…
summary: >-
  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
  TR…
severity: critical
cvss: 9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H'
cwe:
  - CWE-89
  - CWE-115
published: '2026-07-31'
updated: '2026-08-01'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-17351'
references:
  - url: >-
      https://github.com/pgadmin-org/pgadmin4/commit/bf4792444446f0e7ab721d23cbd6bfe6afaa7a8b
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
  - url: >-
      https://github.com/pgadmin-org/pgadmin4/commit/ef76102bcd1cdb544eb9b4ef18d3382f22b76752
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
  - url: 'https://github.com/pgadmin-org/pgadmin4/issues/10192'
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
tags:
  - nvd
  - exploit-available
epss: 0.00483
epssPercentile: 0.39056
ingestedAt: '2026-08-02T00:16:16.215Z'
exploits:
  github: 1
  githubRepos:
    - >-
      https://github.com/Hunt-Benito/pgadmin-ai-assistant-sql-injection-cve-2026-17351-lexer-differential-bypass
  checkedAt: '2026-09-26T09:05:39.004Z'
exploitAvailable: true
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.