Critical severity · published Sep 9, 2026
CVE-2026-87911
Read-only enforcement bypass enabling operating system command execution in the SQL validation component of Amazon awslabs postgres-mcp-server
9.6
CVSS
1.7%
EPSS
No
On KEV
Description
An OS command injection weakness in the read-only enforcement of the SQL validation component in Amazon awslabs postgres-mcp-server before 1.1.7 might allow an unauthenticated actor to execute operating system commands on the host of a self-managed PostgreSQL server by placing a crafted COPY ... TO PROGRAM statement into content that is processed when an authenticated user interacts with the MCP server in its default read-only mode.
To remediate this issue, users should upgrade to version 1.1.7 or later.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.7% · higher than 78% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AL
AWS Labs postgres MCP Server · AWS
before 1.1.7 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-87911
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-87911
aws.amazon.com
https://aws.amazon.com/security/security-bulletins/2026-104-aws/
github.com
https://github.com/awslabs/mcp/security/advisories/GHSA-fph8-pg5w-78fv
pypi.org
https://pypi.org/project/awslabs.postgres-mcp-server/1.1.7/