CVE-2026-17351 — pgAdmin 4: AI Assistant read-only transaction bypass via sqlparse/PostgreSQL lexer disagreement (incomplete fix for CVE-2026-12045)
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Pgadmin Pgadmin 4, Pgadmin.org pgAdmin 4).
- Apply the fixed version or the patch documented under Remediation.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Pgadmin | Pgadmin 4 | ≥ 9.13 and < 9.17 | Vulnerable | NIST National Vulnerability Database |
| Pgadmin.org | pgAdmin 4 | ≥ 9.13 and < 9.17 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.4 | CVSS 4.0 | Critical | — | — | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 via NIST National Vulnerability Database |
| 9.4 | CVSS 4.0 | Critical | — | — | PostgreSQL via CVE Program (cve.org) e CISA ADP |
| 9.0 | CVSS 3.1 | Critical | 2.3 | 6.0 | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 via NIST National Vulnerability Database |
| 9.0 | CVSS 3.1 | Critical | 2.3 | 6.0 | nvd@nist.gov via NIST National Vulnerability Database |
| 9.0 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.0 | CVSS 3.1 | Critical | — | — | PostgreSQL via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 15, 2026 → Oct 27, 2026 · 12 reading(s) · max 0.48%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · pgadmin.org/pgadmin 4
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 9.0
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 23, 2026 – Oct 23, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-86864 pgAdmin 4: Argument and connection-string injection via the database field in the Backup tool Sep 17, 2026
- Medium CVE-2026-86861 pgAdmin 4: File Manager save_file writes through a symbolic link planted after the containment check Sep 17, 2026
- Medium CVE-2026-86862 pgAdmin 4: Connection-string injection via the database field in the Restore and Maintenance tools Sep 17, 2026
- Critical CVE-2026-86863 pgAdmin 4: Authentication bypass via a client-controlled identity header in Webserver authentication mode Sep 17, 2026
- Critical CVE-2026-17566 pgAdmin 4: RCE via backslash-escape mismatch in Import/Export Data query guard (incomplete defense, sibling gap to CVE-2025-13780) Jul 31, 2026
- Medium CVE-2026-17348 pgAdmin 4: Missing authentication decorator on Constraints, preferences, Debugger and Schema Diff routes allows unauthenticated access in SERVER mode (incomplete fix for CVE-2026-12046) Jul 31, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-17351 is "pgAdmin 4: AI Assistant read-only transaction bypass via sqlparse/PostgreSQL lexer disagreement (incomplete fix for CVE-2026-12045)", rated Critical. It affects Pgadmin 4 (Pgadmin); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.0 describes technical severity. EPSS 0.48% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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