SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-47770

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).

MEDIUM 6.8EPSS 0.15%

Does this matter?

Lower severity and a low EPSS score (0.15%). Track it; it rarely justifies an emergency change on its own.

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 4.0
6.8 MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.15% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-674
Affected
jqlang/jq
Source
security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.