# CVE-2026-85063: node-csv: Prototype replacement still reachable via columns path

> Attackers can exploit prototype pollution in node-csv to inject malicious data and potentially execute code when specific parsing options are enabled.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** CLEANSTART-2026-LJ34730, CLEANSTART-2026-OY61738, CLEANSTART-2026-WQ57652, DEBIAN-CVE-2026-85063, ECHO-2240-6ce7-c82e, GHSA-8cw4-87c7-c6xx, MINI-h5vp-4fpq-jqfg, MINI-jfq6-w7ph-3pp7, MINI-vv68-q6rw-5qw4, UBUNTU-CVE-2026-85063

## What is CVE-2026-85063?

CVE-2026-85063 is a medium-severity code injection vulnerability in adaltas node-csv, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

node-csv is a full-featured CSV parser with a simple API that is tested against large datasets. Prior to 7.0.2, csv-parse with the columns and group_columns_by_name options enabled treats a duplicate __proto__ header as an existing property in packages/csv-parse/lib/api/index.js, assigns an attacker-controlled array through obj['__proto__'], and replaces the parsed record object's prototype. A malicious CSV header can therefore inject inherited array values into the returned record, hide those inherited values from JSON serialization, and affect property enumeration and type or shape checks in applications that process the record. This issue is fixed in version 7.0.2.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2026-85063?

2 open source packages ship an affected version, including csv-parse.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `csv-parse` | npm | All versions | 7.0.2 |
| `csv-parse` | npm | All versions | 7.0.2 |

## How do I fix CVE-2026-85063?

Upgrade csv-parse to 7.0.2 or later.

## Is CVE-2026-85063 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85063 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85063 and fix it if it is affected.

What it is: CVE-2026-85063 is a medium-severity code injection vulnerability in adaltas node-csv, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85063 exists.

Affected packages and fixed versions:
- csv-parse (npm): affected all versions; fixed in 7.0.2
- csv-parse (npm): affected all versions; fixed in 7.0.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-85063/ (Markdown: https://insights.sbomify.com/CVE-2026-85063/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85063
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85063
- OSV: https://osv.dev/vulnerability/CVE-2026-85063

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85063/
Summaries are generated and may contain mistakes; the official description above is the record.