CVE-2026-85063: node-csv Prototype Replacement Still Reachable Vulnerability

MODERATE
Advisory Identifier: GHSA-8cw4-87c7-c6xx
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CWE-1321
Published
Advisory Summary

CVE-2026-85063 is a MODERATE prototype replacement still reachable vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting node-csv libraries in the npm ecosystem. The issue involves prototype replacement still reachable via columns path. Remediation is available by upgrading affected packages to version 7.0.2.

CVE-2026-85063 at a Glance

CVE Identifier CVE-2026-85063
GHSA Identifier GHSA-8cw4-87c7-c6xx
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product node-csv
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-85063

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

csv-parse fixed: 7.0.2 
npm install csv-parse@7.0.2
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 csv-parse

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-85063, inspect your project dependencies using npm:

npm ls csv-parse

Analyze the terminal output to locate any version of node-csv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.0.2), your application is affected.

Note: The npm ls csv-parse 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-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In node-csv, 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

### Impact With columns: true and group_columns_by_name: true, a duplicated __proto__ header causes the duplicate-column branch to assign an array to obj['__proto__'], invoking the __proto__ setter and replacing the parsed record object's prototype with attacker-controlled data. Fixed in 7.0.2 (Object.hasOwn duplicate check + Object.defineProperty assignment). ### Patches The problem been patched. ### Workarounds Disable usage of both the columns and group_columns_by_name options. ### References issue #496, PR #497

CVE-2026-85063 Affected node-csv Versions

1 component(s)
Fixed Versions:
7.0.2
Product / Package Ecosystem Affected Versions Fixed Version
csv-parse
npm/csv-parse
npm
< 7.0.2
7.0.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/adaltas/node-csv/security/advisories/GHSA-8cw4-87c7-c6xx
NVD — CVE-2026-85063 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85063
node-csv Source Repository REPOSITORY
https://github.com/adaltas/node-csv/issues/496
node-csv Source Repository REPOSITORY
https://github.com/adaltas/node-csv/pull/497
Security Fix Commit FIX COMMIT
https://github.com/adaltas/node-csv/commit/eb4d1484589c976dcb977db8dd0b90e015a6f66e
node-csv Source Repository REPOSITORY
https://github.com/adaltas/node-csv

Frequently Asked Questions

What is CVE-2026-85063?
CVE-2026-85063 is a security vulnerability in node-csv involving Prototype replacement still reachable via columns path under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which node-csv versions are affected?
Affected versions include releases prior to 7.0.2 across affected packages: csv-parse.
What version fixes CVE-2026-85063?
Upgrading to 7.0.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is csv-parse affected?
Yes, csv-parse is affected in releases prior to 7.0.2. Upgrade your dependency to 7.0.2 or later.
What CWE is associated with CVE-2026-85063?
CVE-2026-85063 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2026-85063?
Run the dependency tree command: 'npm ls csv-parse'. 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-8cw4-87c7-c6xx",
  "modified" : "2026-09-08T18:01:39Z",
  "published" : "2026-09-08T18:01:39Z",
  "aliases" : [ "CVE-2026-85063" ],
  "summary" : "node-csv: Prototype replacement still reachable via columns path",
  "details" : "### Impact\nWith columns: true and group_columns_by_name: true, a duplicated __proto__  header causes the duplicate-column branch to assign an array to obj['__proto__'], invoking the __proto__ setter and replacing the parsed record object's prototype with attacker-controlled data. Fixed in 7.0.2 (Object.hasOwn duplicate check + Object.defineProperty assignment).\n\n### Patches\nThe problem been patched.\n\n### Workarounds\nDisable usage of both the columns and  group_columns_by_name options.\n\n### References\nissue #496, PR #497",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "csv-parse"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.0.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/adaltas/node-csv/security/advisories/GHSA-8cw4-87c7-c6xx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-85063"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/adaltas/node-csv/issues/496"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/adaltas/node-csv/pull/497"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/adaltas/node-csv/commit/eb4d1484589c976dcb977db8dd0b90e015a6f66e"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/adaltas/node-csv"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-08T18:01:39Z",
    "nvd_published_at" : "2026-09-03T21:17:23Z"
  }
}