Detections
Analytics
CVE-2026-40164
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.
References
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40164.json
https://github.com/jqlang/jq/security/advisories/GHSA-wwj8-gxm6-jc29
https://github.com/jqlang/jq/commit/0c7d133c3c7e37c00b6d46b658a02244fdd3c784
https://bugzilla.redhat.com/show_bug.cgi?id=2458084
https://access.redhat.com/security/cve/CVE-2026-40164
https://access.redhat.com/errata/RHSA-2026:8579
https://access.redhat.com/errata/RHSA-2026:30089
https://access.redhat.com/errata/RHSA-2026:30088
https://access.redhat.com/errata/RHSA-2026:30087
https://access.redhat.com/errata/RHSA-2026:30078
https://access.redhat.com/errata/RHSA-2026:28887
https://access.redhat.com/errata/RHSA-2026:26542
https://access.redhat.com/errata/RHSA-2026:26528
https://access.redhat.com/errata/RHSA-2026:25181
https://access.redhat.com/errata/RHSA-2026:25096
https://access.redhat.com/errata/RHSA-2026:25044
https://access.redhat.com/errata/RHSA-2026:23245
https://access.redhat.com/errata/RHSA-2026:23233
https://access.redhat.com/errata/RHSA-2026:19365
https://access.redhat.com/errata/RHSA-2026:19151
https://access.redhat.com/errata/RHSA-2026:18048
https://access.redhat.com/errata/RHSA-2026:18047
https://access.redhat.com/errata/RHSA-2026:18046
https://access.redhat.com/errata/RHSA-2026:18045
https://access.redhat.com/errata/RHSA-2026:18044
https://access.redhat.com/errata/RHSA-2026:18043
https://access.redhat.com/errata/RHSA-2026:18042
https://access.redhat.com/errata/RHSA-2026:18040
https://access.redhat.com/errata/RHSA-2026:16693