---
id: "CVE-2026-119923"
page: "https://infrastack.ai/live/CVE-2026-119923"
kind: "vulnerability"
aliases: ["CVE-2026-119923"]
title: "A heap-based buffer overflow in the TDS prelogin parser in the Babelfish for PostgreSQL extension versions 1.0-1.5,\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Babelfish for Aurora PostgreSQL", "fixed": ["1.5.5", "1.17.2", "2.3.5", "2.12.4", "2.13.3", "2.14.2", "2.15.2", "2.16.1", "3.8.4", "3.9.4", "3.10.3", "3.11.2", "3.12.2", "3.13.1", "4.5.5", "4.6.3", "4.7.2", "4.8.2", "4.9.1", "5.1.4", "5.2.3", "5.3.2", "5.4.2", "5.5.1", "6.0.2"], "affected": "1.x <1.5.5, 1.6.0-<1.17.2; 2.x <2.3.5 and gaps below 2.12.4/2.13.3/2.14.2/2.15.2/2.16.1; 3.x <3.8.4 and gaps below 3.9.4/3.10.3/3.11.2/3.12.2/3.13.1; 4.x <4.5.5 and below 4.6.3/4.7.2/4.8.2/4.9.1; 5.x <5.1.4, below 5.2.3/5.3.2/5.4.2, 5.5.0; 6.0.x <6.0.2", "ecosystem": "vendor"}, {"name": "Babelfish for PostgreSQL extension", "fixed": ["4.10", "5.6", "6.1"], "affected": "1.0-1.5, 2.1-2.15, 3.1-3.12, 4.0-4.8, 5.1-5.4", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["aurora-postgresql", "aws", "babelfish", "databases", "infrastructure", "lab-disclosure", "tds", "unauthenticated"]
not_affected_if: ["babelfish-disabled", "patched-version", "tds-port-restricted"]
published_at: "2026-11-06T19:17:39+00:00"
first_seen_at: "2026-11-06T19:24:10+00:00"
updated_at: "2026-11-06T19:43:48+00:00"
sources: [{"source": "lab", "url": "https://aws.amazon.com/security/security-bulletins/rss/2026-166-aws/", "first_seen_at": "2026-11-06T19:24:10+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-06T19:26:16+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119923", "first_seen_at": "2026-11-06T19:43:48+00:00"}]
exploit_sources: []
---

# A heap-based buffer overflow in the TDS prelogin parser in the Babelfish for PostgreSQL extension versions 1.0-1.5,…

Link for people: https://infrastack.ai/live/CVE-2026-119923 (this .md is for agents)

AWS bulletin 2026-166-AWS: CVE-2026-119923 is a memory-safety bug in Babelfish TDS connection-handshake handling that a remote, unauthenticated actor could use to affect confidentiality, integrity and availability of the database process. CVE-2026-119924 is a memory-safety bug in TDS RPC request handling that a remote, authenticated actor could use to read adjacent process memory or cause denial of service. AWS gives no CVSS score and does not say either is exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Babelfish for Aurora PostgreSQL affected 1.x <1.5.5, 1.6.0-<1.17.2; 2.x <2.3.5 and gaps below 2.12.4/2.13.3/2.14.2/2.15.2/2.16.1; 3.x <3.8.4 and gaps below 3.9.4/3.10.3/3.11.2/3.12.2/3.13.1; 4.x <4.5.5 and below 4.6.3/4.7.2/4.8.2/4.9.1; 5.x <5.1.4, below 5.2.3/5.3.2/5.4.2, 5.5.0; 6.0.x <6.0.2 fixed 1.5.5, 1.17.2, 2.3.5, 2.12.4, 2.13.3, 2.14.2, 2.15.2, 2.16.1, 3.8.4, 3.9.4, 3.10.3, 3.11.2, 3.12.2, 3.13.1, 4.5.5, 4.6.3, 4.7.2, 4.8.2, 4.9.1, 5.1.4, 5.2.3, 5.3.2, 5.4.2, 5.5.1, 6.0.2
- vendor:Babelfish for PostgreSQL extension affected 1.0-1.5, 2.1-2.15, 3.1-3.12, 4.0-4.8, 5.1-5.4 fixed 4.10, 5.6, 6.1

## How to check

Only clusters with Babelfish enabled are affected. Find your Aurora PostgreSQL engine version and its included Babelfish version, then compare against the bulletin ranges (e.g. Aurora Babelfish 1.x <1.5.5 or 1.6.0-1.17.1; 2.x <2.3.5; 3.x <3.8.4; 4.x <4.5.5; 5.x <5.1.4; 6.0.x <6.0.2). Also check whether TDS port 1433 is reachable from untrusted networks in VPC security groups. Workaround until upgraded (per AWS): restrict TDS port 1433 to trusted sources with VPC security groups.

## Fix

Upgrade Aurora PostgreSQL to a fixed version (Babelfish version in parentheses) or later and apply pending maintenance: 13.9.16 (1.5.5), 13.23.3 (1.17.2), 14.6.16 (2.3.5), 14.17.8 (2.12.4), 14.18.6 (2.13.3), 14.19.5 (2.14.2), 14.20.5 (2.15.2), 14.22.3 (2.16.1), 14.23.1 (2.17.0), 15.10.8 (3.8.4), 15.12.8 (3.9.4), 15.13.6 (3.10.3), 15.14.5 (3.11.2), 15.15.5 (3.12.2), 15.17.3 (3.13.1), 15.18.1 (3.14.0), 16.8.8 (4.5.5), 16.9.6 (4.6.3), 16.10.5 (4.7.2), 16.11.5 (4.8.2), 16.13.3 (4.9.1), 16.14.1 (4.10.0), 17.4.8 (5.1.4), 17.5.6 (5.2.3), 17.6.5 (5.3.2), 17.7.5 (5.4.2), 17.9.3 (5.5.1), 17.10.1 (5.6.0), 18.3.4 (6.0.2), 18.4.1 (6.1.0). Open-source Babelfish for PostgreSQL: 4.10, 5.6, 6.1.

## Timeline

- 2026-11-06T19:24:10+00:00 lab https://aws.amazon.com/security/security-bulletins/rss/2026-166-aws/ — AWS: CVE-2026-119923 and CVE-2026-119924: Issues with Babelfish for Aurora PostgreSQL
- 2026-11-06T19:26:16+00:00 analyst — Read AWS bulletin 2026-166-AWS (primary). No CVSS, exploitation or PoC stated; X not checked. Fix versions and workaround from the bulletin.
- 2026-11-06T19:43:48+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119923

## Documents

- [advisory] AWS-2026-166: Issues with Babelfish for Aurora PostgreSQL https://aws.amazon.com/security/security-bulletins/rss/2026-166-aws/
- [fix] AWS-2026-166: Issues with Babelfish for Aurora PostgreSQL https://aws.amazon.com/security/security-bulletins/rss/2026-166-aws/
- [fix] Release notes: github.com https://github.com/babelfish-for-postgresql/babelfish-for-postgresql/releases/tag/BABEL_4_10_0__PG_16_14
- [fix] Release notes: github.com https://github.com/babelfish-for-postgresql/babelfish-for-postgresql/releases/tag/BABEL_5_6_0__PG_17_10
- [fix] Release notes: github.com https://github.com/babelfish-for-postgresql/babelfish-for-postgresql/releases/tag/BABEL_6_1_0__PG_18_4
- [mentions] AWS-2026-166: Issues with Babelfish for Aurora PostgreSQL https://aws.amazon.com/security/security-bulletins/rss/2026-166-aws/

## From the sources

CVE-2026-119923 and CVE-2026-119924: Issues with Babelfish for Aurora PostgreSQL

### CVE-2026-119923 and CVE-2026-119924: Issues with Babelfish for Aurora PostgreSQL

Bulletin ID: 2026-166-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 11/06/2026 10:00 AM PST

Description:

Babelfish for PostgreSQL extension enables users to run SQL Server workloads without modifying their applications. Babelfish is developed as an OpenSource project using the PostgreSQL’s extension model. It is owned and maintained by AWS https://github.com/babelfish-for-postgresql/babelfish_extensions/. 

Babelfish for Aurora PostgreSQL enables Amazon Aurora PostgreSQL to understand the SQL Server wire protocol (TDS), allowing applications built for SQL Server to connect without changing drivers or rewriting application code.

We identified two issues in the Babelfish TDS protocol layer:

- CVE-2026-119923: A memory-safety issue in the TDS connection-handshake handling could allow a remote, unauthenticated actor to affect the confidentiality, integrity, and availability of the database process.
- CVE-2026-119924: AA memory-safety issue in the TDS remote-procedure-call request handling could allow a remote, authenticated actor to read adjacent process memory or cause a denial of service.

Impacted versions:

- Babelfish for PostgreSQL: - 1.0-1.5 - 2.1-2.15 - 3.1-3.12 - 4.0-4.8 - 5.1-5.4 
- Babelfish for Aurora PostgreSQL: - 1.x: <1.5.5; >=1.6.0 AND <1.17.2 - 2.x: <2.3.5; >=2.4.0 AND <2.12.4; >=2.13.0 AND <2.13.3; >=2.14.0 AND <2.14.2; >=2.15.0 AND <2.15.2; >=2.16.0 AND <2.16.1 - 3.x: <3.8.4; >=3.9.0 AND <3.9.4; >=3.10.0 AND <3.10.3; >=3.11.0 AND <3.11.2; >=3.12.0 AND <3.12.2; >=3.13.0 AND <3.13.1 - 4.x: <<4.5.5; >=4.6.0 AND <4.6.3; >=4.7.0 AND <4.7.2; >=4.8.0 AND <4.8.2; >=4.9.0 AND <4.9.1 - 5.x: <5.1.4; >=5.2.0 AND <5.2.3; >=5.3.0 AND <5.3.2; >=5.4.0 AND <5.4.2; 5.5.0 - 6.x: >=6.0.0 AND <6.0.2

Resolution:

This issue has been addressed in Babelfish for PostgreSQL extension versions 4.10, 5.6 and 6.1. For Amazon Aurora PostgreSQL customers with Babelfish enabled, upgrade your cluster to one of the following Aurora PostgreSQL versions (included Babelfish version in parentheses) or later, and apply any pending maintenance to ensure you are on the latest patch: 13.9.16 (1.5.5), 13.23.3 (1.17.2), 14.6.16 (2.3.5), 14.17.8 (2.12.4), 14.18.6 (2.13.3), 14.19.5 (2.14.2), 14.20.5 (2.15.2), 14.22.3 (2.16.1), 14.23.1 (2.17.0), 15.10.8 (3.8.4), 15.12.8 (3.9.4), 15.13.6 (3.10.3), 15.14.5 (3.11.2), 15.15.5 (3.12.2), 15.17.3 (3.13.1), 15.18.1 (3.14.0), 16.8.8 (4.5.5), 16.9.6 (4.6.3), 16.10.5 (4.7.2), 16.11.5 (4.8.2), 16.13.3 (4.9.1), 16.14.1 (4.10.0), 17.4.8 (5.1.4), 17.5.6 (5.2.3), 17.6.5 (5.3.2), 17.7.5 (5.4.2), 17.9.3 (5.5.1), 17.10.1 (5.6.0), 18.3.4 (6.0.2), 18.4.1 (6.1.0).

Workarounds:

Restrict network access to the TDS port (default 1433) to trusted sources using VPC security groups until the upgrade is applied.

References:

- CVE-2026-119923
- CVE-2026-119924

 Please email aws-security@amazon.com with any security questions or concerns.

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