CVE-2026-126196 pgEdge Postgres MCP Server read-only mode can be bypassed by SQL statement smuggling through query_database
Callers can smuggle SQL through query_database on read-only connections to modify data and leave later calls writable; pgEdge users should care.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- None listed
What is CVE-2026-126196?
CVE-2026-126196 is a high-severity security feature bypass vulnerability in pgedge-postgres-mcp, published on 12 Nov 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
pgEdge Postgres MCP Server enables SQL queries against PostgreSQL databases through Model Context Protocol compatible clients. Prior to 1.1.0, query_database on a read_only connection could send unrecognized statements through pgx Exec without bind parameters, selecting PostgreSQL's simple query protocol and allowing multiple semicolon-separated statements in one request. A caller could combine transaction or session state changes with database writes, and pooled session state could leave later calls writable, when the connecting role held write privileges. The flaw affected deployments relying on read_only as a safety boundary, could compromise integrity and availability, and did not add confidentiality impact beyond the reads already permitted by the connection. This issue is fixed in 1.1.0.
Which versions are affected by CVE-2026-126196?
Only installations with a non-default setting turned on are exposed.
How do I fix CVE-2026-126196?
No fix has been published for CVE-2026-126196 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version, and do not rely on a single control for protection. More about Security feature bypass.
Is CVE-2026-126196 being exploited?
There is no known exploitation of CVE-2026-126196 in the wild and no public exploit code.
Sources
Also known as GHSA-j7mp-839j-jrm7.