CVE-2026-40164
jq: jq: Denial of Service via crafted JSON object causing hash collisions
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 14, 2026
Updated · October 25, 2026
Description
A flaw was found in jq, a command-line JSON processor. A remote attacker could exploit this vulnerability by providing a specially crafted JSON object. This object leverages a weakness in jq's hashing algorithm, which uses a hardcoded, publicly known seed. By crafting the JSON object to cause hash collisions, an attacker can degrade the performance of JSON object hash table operations, leading to significant CPU exhaustion and a denial of service (DoS) for systems processing the malicious JSON data.
CVSS score applicability
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.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-341 · Predictable from Observable State