# CVE-2023-32695: Insufficient validation when decoding a Socket.IO packet

> A specially crafted Socket.IO packet causes an uncaught exception, crashing the Node.js server process.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2023
- **Updated:** 13 Jan 2025
- **Also known as:** DEBIAN-CVE-2023-32695, GHSA-cqmj-92xf-r6r9, ROOT-APP-NPM-CVE-2023-32695, UBUNTU-CVE-2023-32695

## What is CVE-2023-32695?

CVE-2023-32695 is a high-severity denial of service vulnerability in socketio socket.io-parser, published on 27 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

socket.io parser is a socket.io encoder and decoder written in JavaScript complying with version 5 of socket.io-protocol. A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. A patch has been released in version 4.2.3.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-32695?

6 open source packages ship an affected version, including socket.io-parser. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `socket.io-parser` | npm | All versions | 3.3.4 |
| `socket.io-parser` | npm | All versions | 3.3.4 |
| `socket.io-parser` | npm | From 3.4.0 | 3.4.3 |
| `socket.io-parser` | npm | From 3.4.0 | 3.4.3 |
| `socket.io-parser` | npm | From 4.0.4 | 4.2.3 |
| `socket.io-parser` | npm | From 4.0.4 | 4.2.3 |

Products: Socket Socket.io-Parser.

## How do I fix CVE-2023-32695?

Upgrade socket.io-parser to a fixed version for your release line: 3.3.4, 3.4.3 or 4.2.3.

## Is CVE-2023-32695 being exploited?

There is no known exploitation of CVE-2023-32695 in the wild and no public exploit code.

## Other vulnerabilities in socketio socket.io-parser

- [CVE-2022-2421](https://insights.sbomify.com/CVE-2022-2421/): Socket.io - Improper type validation in attachment parsing (critical 10.0)
- [CVE-2026-33151](https://insights.sbomify.com/CVE-2026-33151/): socket.io allows an unbounded number of binary attachments (high 8.7)
- [CVE-2020-36049](https://insights.sbomify.com/CVE-2020-36049/): Resource exhaustion in socket.io-parser (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-32695 and fix it if it is affected.

What it is: CVE-2023-32695 is a high-severity denial of service vulnerability in socketio socket.io-parser, published on 27 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-32695 in the wild and no public exploit code.

Affected packages and fixed versions:
- socket.io-parser (npm): affected all versions; fixed in 3.3.4
- socket.io-parser (npm): affected all versions; fixed in 3.3.4
- socket.io-parser (npm): affected from 3.4.0; fixed in 3.4.3
- socket.io-parser (npm): affected from 3.4.0; fixed in 3.4.3
- socket.io-parser (npm): affected from 4.0.4; fixed in 4.2.3
- socket.io-parser (npm): affected from 4.0.4; fixed in 4.2.3

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-2023-32695/ (Markdown: https://insights.sbomify.com/CVE-2023-32695/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-32695
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-32695
- OSV: https://osv.dev/vulnerability/CVE-2023-32695

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-32695/
Summaries are generated and may contain mistakes; the official description above is the record.