CVE-2026-96883 in pgcollection
Summary
by MITRE • 09/24/2026
pgcollection is an open source extension to PostgreSQL. A type confusion issue in AWS pgcollection 2.0.0 through 2.1.1 might allow an authenticated remote user to execute arbitrary code as the postgres operating system user via crafted SQL statements that rely on mismatched type metadata in collection value retrieval and array conversion functions.
To remediate this issue, users should upgrade to version 2.1.2 or later.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified within AWS pgcollection versions 2.0.0 through 2.1.1 represents a critical security flaw rooted in improper type handling during the processing of collection data structures. As an open-source extension for PostgreSQL, pgcollection is designed to facilitate advanced data manipulation and retrieval operations. However, the underlying implementation contains a logic error where mismatched type metadata leads to a condition known as type confusion. This specific class of vulnerability occurs when software incorrectly assumes that a variable or object belongs to one data type while it actually holds another, leading to unpredictable behavior during execution. In this context, the flaw is triggered specifically through crafted SQL statements that interact with collection value retrieval and array conversion functions. When an authenticated user submits these maliciously constructed queries, the extension fails to properly validate or cast the incoming data types against their expected metadata definitions.
The operational impact of this type confusion vulnerability is severe, as it allows for arbitrary code execution under the context of the postgres operating system user. This privilege level typically possesses broad access rights within the database environment and potentially on the host machine itself if file system permissions are not strictly segregated. By exploiting the mismatch in type metadata, an attacker can manipulate memory operations or function calls to execute shell commands or other malicious payloads directly on the server hosting the PostgreSQL instance. This effectively bypasses standard authentication mechanisms since the vulnerability requires only authenticated access, which is often easier for attackers to obtain through credential theft or weak password policies. The ability to escalate privileges from a database user to an operating system-level compromise significantly expands the attack surface, potentially leading to full control over the underlying infrastructure and lateral movement within the network.
From a classification perspective, this vulnerability aligns with CWE-843, which describes access of incorrect type or accessing memory as wrong type. This misclassification leads directly to CWE-94, commonly known as Improper Control of Generation of Code (Code Injection), because the flawed logic enables the execution of arbitrary code. In terms of tactical mapping within the MITRE ATT&CK framework, this exploit falls under T1059, Command and Scripting Interpreter, specifically leveraging SQL commands to achieve remote code execution. The attack vector is classified as Network with Authentication Required (T1190), indicating that while it can be exploited remotely, valid credentials are necessary to initiate the malicious payload. This highlights the importance of not only securing network perimeters but also enforcing strict access controls and input validation within database applications themselves.
To mitigate this risk, immediate action is required by upgrading the pgcollection extension to version 2.1.2 or any later release where these type handling logic errors have been corrected. Beyond software updates, organizations should implement defense-in-depth strategies such as principle of least privilege for database accounts, ensuring that the postgres user does not possess unnecessary operating system permissions. Additionally, deploying Web Application Firewalls (WAFs) with specific rules to detect anomalous SQL patterns related to collection functions can provide an additional layer of monitoring and protection against exploitation attempts while patching efforts are underway. Regular auditing of extension usage and strict validation of input data types at the application level further reduce the likelihood of successful type confusion attacks in PostgreSQL environments.