{"id":"AZL-82934","summary":"CVE-2026-40164 affecting package jq for versions less than 1.7.1-5","details":"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.","modified":"2026-08-30T05:26:50Z","published":"2026-04-14T00:16:07Z","upstream":["CVE-2026-40164"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40164"}],"affected":[{"package":{"name":"jq","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/jq"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.7.1-5"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-82934.json"}}],"schema_version":"1.9.0"}