Vulnerability in Jqlang Jq
CVE-2026-47770
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Jqlang Jq — versions < 1.8.2
Weakness classification (CWE)
References
- github.com/jqlang/jq/security/advisories/GHSA-3pgx-frr7-3jxp (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-47770?
- CVE-2026-47770 is a medium-severity vulnerability in Jqlang Jq, classified under Uncontrolled Recursion. CVSS score: 5.5/10. Published 2026-06-25.
- How severe is CVE-2026-47770?
- Medium severity. CVSS v3 base score is 5.5 out of 10.