Denial of Service via deeply nested array comparison

Summary

jq is a command-line JSON processor. Prior to 1.8.2, comparing two sufficiently deeply nested arrays with the == operator exhausts the C stack on jq's ordinary command-line surface, resulting in denial of service via stack exhaustion (uncontrolled recursion). The crash occurs in jq's recursive structural comparison code, with the recursion repeating through jvp_array_equal() and jv_equal() in src/jv.c when comparing deeply nested arrays; a nearby sort comparator path through jv_cmp() in src/jv_aux.c overflows the stack at a larger nesting depth from the same missing recursion guard. Anyone running jq comparisons on attacker-controlled deeply nested JSON values, or embedding jq in a context where untrusted data can reach the == comparison path, is affected. This vulnerability is fixed in 1.8.2. A flaw was found in jq, a command-line JSON processor. This vulnerability allows a local user or an attacker providing malicious input to cause a denial of service (DoS) by comparing two sufficiently deeply nested arrays using the '==' operator. This action exhausts the C stack due to uncontrolled recursion, leading to a crash of the jq process. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H). Weakness: CWE-770. Fixed by RHSA-2026:29986 — update the affected packages (`sudo dnf update`). Affected Red Hat products: Red Hat Hardened Images.