Overview

The Apollo Compiler, a query-based compiler for the GraphQL query language, is susceptible to a vulnerability that could lead to denial of service attacks and potential system compromise or data leakage. This vulnerability, known as CVE-2025-31496, is particularly significant as it affects any system using versions of the Apollo Compiler prior to 1.27.0. It is of utmost importance to address this vulnerability due to its potential to consume excessive system resources and compromise data security.

Vulnerability Summary

CVE ID: CVE-2025-31496
Severity: High (7.5 CVSS)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Excessive resource consumption potentially leading to denial of service and potential for system compromise or data leakage

Affected Products

Product | Affected Versions

Apollo Compiler | Prior to 1.27.0

How the Exploit Works

The vulnerability lies in the handling of named fragments during query validation in the Apollo Compiler. In versions prior to 1.27.0, named fragments were processed once per fragment spread in some cases, which led to exponential resource usage when deeply nested and reused fragments were involved. An attacker can exploit this vulnerability by sending a specially crafted GraphQL query with deeply nested and reused named fragments, causing the system to use excessive resources, potentially leading to a denial of service.

Conceptual Example Code

The following is a conceptual example of a GraphQL query that could potentially exploit this vulnerability:

POST /graphql HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"query" : "{
...Fragment
}
fragment Fragment on Type {
field
...Fragment
}"
}

In the above example, the fragment “Fragment” is being recursively reused within itself, leading to a deeply nested query that could cause exponential resource usage, potentially leading to a denial of service.