SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-77414

Prior to 1.8.8 and 2.2.1, the src/jsonata.js environment.lookup function used a bypassable hasOwnProperty check.

CRITICAL 9.3EPSS 0.43%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

JSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.1, the src/jsonata.js environment.lookup function used a bypassable hasOwnProperty check. Crafted expressions could use $hasOwnProperty, $spread, $string, prototype access, and $constructor to reach the object prototype and invoke process.getBuiltinModule with child_process, executing arbitrary code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.1.

CVSS 4.0
9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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
0.43% probability · 37th percentile
CISA KEV
Not listed
Weakness
CWE-94
Source
security-advisories@github.com

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