CVE-2026-40164

April 14, 2026, 12:16 a.m.

7.5
High

Description

jq is a command-line JSON processor. Before commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784, jq used MurmurHash3 with a hardcoded, publicly visible seed (0x432A9843) for all JSON object hash table operations, which allowed an attacker to precompute key collisions offline. By supplying a crafted JSON object (~100 KB) where all keys hashed to the same bucket, hash table lookups degraded from O(1) to O(n), turning any jq expression into an O(n²) operation and causing significant CPU exhaustion. This affected common jq use cases such as CI/CD pipelines, web services, and data processing scripts, and was far more practical to exploit than existing heap overflow issues since it required only a small payload. This issue has been patched in commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784.

Product(s) Impacted

Vendor Product Versions
Jq
  • Jq
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-328
Use of Weak Hash
The product uses an algorithm that produces a digest (output value) that does not meet security expectations for a hash function that allows an adversary to reasonably determine the original input (preimage attack), find another input that can produce the same hash (2nd preimage attack), or find multiple inputs that evaluate to the same hash (birthday attack).

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a jq jq / / / / / / / /

References

https://github.com/jqlang/jq/commit/0c7d133c3c7e37c00b6d46b658a02244fdd3c784
https://github.com/jqlang/jq/security/advisories/GHSA-wwj8-gxm6-jc29

Tags

[email protected]
CWE-328
2026-04-14
CVE-2026-40164

CVSS Score

7.5 / 10

CVSS Data - 3.1

  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Privileges Required: NONE
  • Scope: UNCHANGED
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: HIGH

    • CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

    View Vector String

Timeline

Published: April 14, 2026, 12:16 a.m.
Last Modified: April 14, 2026, 12:16 a.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.