CVE-2025-9403

A vulnerability has been identified in the jq JSON processor where malformed JSON input containing invalid Unicode escape sequences can trigger an assertion failure in the test suite’s parsing consistency checks. This flaw arises from inconsistencies between expected and reparsed JSON values during serialization and deserialization, potentially allowing an attacker to exploit the issue by supplying specially crafted JSON data to cause abnormal termination or denial of service during test execution, highlighting weaknesses in jq’s parsing reliability.

This vulnerability is limited to jq’s internal test framework and does not affect jq’s core functionality in production use. Exploitation requires supplying malformed JSON with invalid Unicode escape sequences during test execution, which can trigger an assertion failure and abnormal termination of the test suite. The issue is rated Low severity as it only causes test crashes in debug or development environments, without exposing sensitive data, compromising system integrity, or affecting jq’s normal JSON processing in production.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No action is required for production users, as the vulnerability only affects jq’s internal test framework and does not impact its core JSON processing functionality. Standard deployments of jq remain unaffected. Developers and testers are advised to avoid running the test suite with untrusted or malformed JSON input until a fix is applied.