Medium severity · published Jun 25, 2026
CVE-2026-47770
jq: stack overflow in deep structural equality
5.5
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JQ
jq · jqlang
< 1.8.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-47770
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-47770
Exploit
https://github.com/jqlang/jq/security/advisories/GHSA-3pgx-frr7-3jxp
More from jq
8.1
CVE-2024-53427
decNumberCopy in decNumber.c in jq through 1.7.1 does not properly consider that NaN is interpreted as numeric, which has a resultant stack-based buffer overflow and out-of-bounds…
7.5
CVE-2026-40164
jq: Algorithmic complexity DoS via hardcoded MurmurHash3 seed
7.5
CVE-2026-32316
jq: Integer overflow in jvp_string_append() allows Heap-based Buffer Overflow
7.5
CVE-2025-48060
jq is a command-line JSON processor
7.5
CVE-2023-49355
decToString in decNumber/decNumber.c in jq 88f01a7 has a one-byte out-of-bounds write via the " []-1.2e-1111111111" input
