CVE-2026-12208: jsonata Function Binding Prototype Pollution Vulnerability

MODERATE
Advisory Identifier: GHSA-663r-x48j-fg8p
Share
CVSS 5.3
CWE-94
Published
Advisory Summary

CVE-2026-12208 is a MODERATE (CVSS 5.3) function binding prototype pollution vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting jsonata libraries in the npm ecosystem. The issue involves function binding prototype pollution via hasownproperty override. Remediation is available by upgrading affected packages to version 1.8.8, 2.2.1.

CVE-2026-12208 at a Glance

CVE Identifier CVE-2026-12208
GHSA Identifier GHSA-663r-x48j-fg8p
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product jsonata
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-12208

To remediate this vulnerability, upgrade all affected jsonata dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

jsonata fixed: 1.8.8 
npm install jsonata@1.8.8
jsonata fixed: 2.2.1 
npm install jsonata@2.2.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls jsonata

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-12208, inspect your project dependencies using npm:

npm ls jsonata

Analyze the terminal output to locate any version of jsonata in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.8.8), your application is affected.

Note: The npm ls jsonata command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In jsonata, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A weakness has been identified in jsonata-js jsonata up to 2.2.0. The affected element is the function createFrame of the file src/jsonata.js of the component Function Binding Frame System. This manipulation causes improperly controlled modification of object prototype attributes. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

CVE-2026-12208 Affected jsonata Versions

2 component(s)
Fixed Versions:
1.8.82.2.1
Product / Package Ecosystem Affected Versions Fixed Version
jsonata
npm/jsonata
npm
< 1.8.8
1.8.8
jsonata
npm/jsonata
npm
≥ 2.0.0
< 2.2.1
2.2.1

References

NVD — CVE-2026-12208 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12208
jsonata Source Repository REPOSITORY
https://github.com/jsonata-js/jsonata/pull/799
jsonata Source Repository REPOSITORY
https://github.com/jsonata-js/jsonata/pull/806
Security Fix Commit FIX COMMIT
https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2
Security Fix Commit FIX COMMIT
https://github.com/jsonata-js/jsonata/commit/f09df8416eab8ff44926fc6527c80fb8701de159
jsonata Source Repository REPOSITORY
https://github.com/OriginSecurityX/jsonata-hasownproperty-bypass
jsonata Source Repository REPOSITORY
https://github.com/jsonata-js/jsonata
jsonata Release RELEASE
https://github.com/jsonata-js/jsonata/releases/tag/v1.8.8
jsonata Release RELEASE
https://github.com/jsonata-js/jsonata/releases/tag/v2.2.1
vuldb.com/cve/cve-2026-12208 WEB
https://vuldb.com/cve/CVE-2026-12208
vuldb.com/submit/832446 WEB
https://vuldb.com/submit/832446
vuldb.com/vuln/370850 WEB
https://vuldb.com/vuln/370850
vuldb.com/vuln/370850/cti WEB
https://vuldb.com/vuln/370850/cti

Frequently Asked Questions

What is CVE-2026-12208?
CVE-2026-12208 is a security vulnerability in jsonata involving Function Binding Prototype Pollution via hasOwnProperty Override under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which jsonata versions are affected?
Affected versions include releases prior to 1.8.8, 2.2.1 across affected packages: jsonata.
What version fixes CVE-2026-12208?
Upgrading to 1.8.8, 2.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is jsonata affected?
Yes, jsonata is affected in releases prior to 1.8.8, 2.2.1. Upgrade your dependency to 1.8.8, 2.2.1 or later.
What is the CVSS score of CVE-2026-12208?
CVE-2026-12208 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2026-12208?
CVE-2026-12208 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check npm dependencies for CVE-2026-12208?
Run the dependency tree command: 'npm ls jsonata'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-663r-x48j-fg8p",
  "modified" : "2026-09-08T17:36:19Z",
  "published" : "2026-06-15T03:30:32Z",
  "aliases" : [ "CVE-2026-12208" ],
  "summary" : "jsonata: Function Binding Prototype Pollution via hasOwnProperty Override",
  "details" : "A weakness has been identified in jsonata-js jsonata up to 2.2.0. The affected element is the function createFrame of the file src/jsonata.js of the component Function Binding Frame System. This manipulation causes improperly controlled modification of object prototype attributes. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "jsonata"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.8.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "jsonata"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-12208"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/pull/799"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/pull/806"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/commit/f09df8416eab8ff44926fc6527c80fb8701de159"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/OriginSecurityX/jsonata-hasownproperty-bypass"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jsonata-js/jsonata"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/releases/tag/v1.8.8"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jsonata-js/jsonata/releases/tag/v2.2.1"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/cve/CVE-2026-12208"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/submit/832446"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/370850"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/370850/cti"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-08T17:36:19Z",
    "nvd_published_at" : "2026-06-15T03:16:23Z"
  }
}