CVE-2026-1175: 
NixOS vulnerability analysis and mitigation

CVE-2026-1175 is an information disclosure vulnerability in the GraphQL Directive Handler component of birkir/prime, an open-source self-hosted headless CMS. The flaw causes sensitive information to be exposed through error messages returned by the /graphql endpoint. It affects birkir prime versions up to and including 0.4.0.beta.0 (CPE: cpe:2.3:a:birkir:prime:*:*:*:*:*:*:*:* up to version 0.4.0). The vulnerability was reported via a GitHub issue on January 3, 2026, and published to NVD on January 19, 2026. NIST NVD assigns a CVSS v3.1 base score of 7.5 (High), while the CNA (VulDB) rates it 5.3 (Medium); the CVSS v4.0 score from VulDB is 5.5 (Medium) (GitHub Issue, Red Hat CVE).

The root cause is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) and CWE-209 (Generation of Error Message Containing Sensitive Information). The GraphQL Directive Handler in prime's /graphql endpoint returns verbose error messages that leak internal schema details — including directive names, parameters, and default values — when malformed or introspective queries are submitted. An unauthenticated remote attacker can craft a GraphQL query (e.g., querying __schema { directive } with an intentional field name typo) to trigger a validation error response that reveals server-side directive configurations such as authentication mechanisms, rate-limiting rules, and sensitive field markings. No authentication, special privileges, or user interaction is required to exploit this vulnerability (GitHub Issue, Red Hat CVE).

Successful exploitation allows unauthenticated remote attackers to enumerate the server's GraphQL schema directives, including authentication enforcement directives, rate-limiting configurations, and sensitive field annotations. This information disclosure can serve as a reconnaissance step, enabling attackers to map the application's security architecture and craft more targeted follow-on attacks. The primary impact is to confidentiality; integrity and availability are not directly affected by this vulnerability (GitHub Issue, Red Hat CVE).

A public proof-of-concept exploit is available in the GitHub issue report, consisting of a simple curl command targeting the /graphql endpoint with a crafted introspection query. The EPSS score is approximately 0.029% (very low probability of exploitation in the near term). There is no evidence of active in-the-wild exploitation at this time, and the vulnerability has not been added to the CISA Known Exploited Vulnerabilities (KEV) catalog. The vendor (birkir) had not responded to the disclosure as of the time of publication (GitHub Issue, Red Hat CVE).

1. Reconnaissance: Identify internet-facing instances of birkir/prime CMS (version ≤ 0.4.0.beta.0) using search engines like Shodan or Censys, or by identifying the /graphql endpoint on known targets.
2. Craft a malformed GraphQL introspection query: Construct a query that intentionally references an invalid field on a schema type to trigger a verbose error response, e.g.:

curl -X POST -H "Content-Type: application/json" \
  -d '{"query": "query cop { __schema { directive } }", "operationName": "cop"}' \
  'http://<target>/graphql'

3. Analyze the error response: The server returns a JSON error message such as {"errors":[{"message":"Cannot query field \"directive\" on type \"__Schema\". Did you mean \"directives\"?","extensions":{"code":"GRAPHQL_VALIDATION_FAILED"}}]}, which reveals internal schema field names and suggestions.
4. Enumerate directives: Use GraphQL introspection queries (e.g., { __schema { directives { name args { name } } } }) to further enumerate directive names, argument names, and default values exposed by the server.
5. Map security architecture: Analyze the disclosed directive information to identify authentication enforcement points, rate-limiting configurations, and sensitive field markings, then use this knowledge to craft targeted attacks against the application (GitHub Issue).

• Network: Unusual HTTP POST requests to /graphql containing __schema introspection queries or intentionally malformed field names (e.g., { __schema { directive } }); requests with the User-Agent: oxpecker header as seen in the published PoC.
• Logs: Web server or application logs showing repeated GraphQL validation errors (GRAPHQL_VALIDATION_FAILED) from a single or small set of source IPs; high volume of introspection queries from external IP addresses.
• Application: GraphQL error responses containing schema field suggestions (e.g., "Did you mean \"directives\"?") returned to unauthenticated clients (GitHub Issue).

Organizations running birkir/prime version 0.4.0.beta.0 or earlier should monitor the project's GitHub repository for a patched release, as the vendor had not responded to the disclosure at time of publication. As interim mitigations: restrict access to the /graphql endpoint to authorized users or trusted IP ranges using network-level controls or a reverse proxy; disable GraphQL introspection in production environments; deploy Web Application Firewall (WAF) rules to detect and block malformed or introspective GraphQL queries; and configure the GraphQL server to suppress verbose error messages in production mode (GitHub Issue, Red Hat CVE).

The vulnerability was reported by a researcher (NinjaGPT) via a GitHub issue on January 3, 2026, with a working PoC included. The project maintainer had not responded to the disclosure as of publication. A security advisory was subsequently published by zast.ai covering this and related unpatched vulnerabilities in Prime's GraphQL implementation (zast.ai Advisory). Red Hat tracked the CVE in their security advisory database, indicating broader industry awareness (Red Hat CVE).