---
id: CVE-2023-23631
aliases:
  - GHSA-4gj3-6r43-3wfc
  - GO-2023-1559
title: IPFS go-unixfsnode subject to DOS via HAMT Decoding Panics
summary: IPFS go-unixfsnode subject to DOS via HAMT Decoding Panics
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: ipfs
product: github.com/ipfs/go-unixfsnode
ecosystem: go
affected:
  - github.com/ipfs/go-unixfsnode < 1.5.2
patched:
  - github.com/ipfs/go-unixfsnode 1.5.2
published: '2023-02-10'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:49:56.605610741Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-4gj3-6r43-3wfc'
references:
  - url: >-
      https://github.com/ipfs/go-unixfsnode/security/advisories/GHSA-4gj3-6r43-3wfc
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2023-23631'
  - url: >-
      https://github.com/ipfs/go-unixfsnode/commit/59050ea8bc458ae55246ae09243e6e165923e076
  - url: >-
      https://github.com/ipfs/go-unixfsnode/commit/91b3d39d33ef0cd2aff2c95d50b2329350944b68
  - url: >-
      https://github.com/ipfs/go-unixfsnode/commit/a4ed723727e0bdc2277158337c2fc0d82802d122
  - url: 'https://github.com/ipfs/go-unixfsnode'
  - url: 'https://pkg.go.dev/vuln/GO-2023-1559'
tags:
  - osv
  - go
epss: 0.00908
epssPercentile: 0.58324
ingestedAt: '2026-09-12T03:13:01.753Z'
---

## Overview

## Impact

Trying to read malformed HAMT sharded directories can cause panics and virtual memory leaks.
If you are reading untrusted user input, an attacker can then trigger a panic.

This is caused by a bogus fanout parameter in the HAMT directory nodes.
This includes checks returned in [ipfs/go-bitfield GHSA-2h6c-j3gf-xp9r](https://github.com/ipfs/go-bitfield/security/advisories/GHSA-2h6c-j3gf-xp9r), as well as limiting the fanout to <= 1024 (to avoid attempts of arbitrary sized allocations).

## Patches
- https://github.com/ipfs/go-unixfsnode/commit/91b3d39d33ef0cd2aff2c95d50b2329350944b68
- https://github.com/ipfs/go-unixfsnode/commit/a4ed723727e0bdc2277158337c2fc0d82802d122

## References

* https://github.com/ipfs/go-unixfs/security/advisories/GHSA-q264-w97q-q778
* https://github.com/ipfs/go-bitfield/security/advisories/GHSA-2h6c-j3gf-xp9r


## Affected packages

- `github.com/ipfs/go-unixfsnode < 1.5.2`

## Remediation

Upgrade to a patched release:

- `github.com/ipfs/go-unixfsnode 1.5.2`