---
id: GHSA-9v8h-qqgm-4m35
title: >-
  Brotli: Out-of-bounds write in the Brotli decoder ("Node2Shell") also affects
  the PyPI Brotli package
summary: >-
  Brotli: Out-of-bounds write in the Brotli decoder ("Node2Shell") also affects
  the PyPI Brotli package
severity: critical
cwe:
  - CWE-252
vendor: brotli
product: brotli
ecosystem: pip
affected:
  - 'brotli >= 1.0.3, < 1.2.1'
  - 'brotlicffi >= 1.0.3, < 1.2.1.0'
patched:
  - brotli 1.2.1
  - brotlicffi 1.2.1.0
published: '2026-10-22'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T19:08:11Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-9v8h-qqgm-4m35'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-111497'
  - url: >-
      https://nodejs.org/en/blog/vulnerability/october-2026-security-releases#nodejs-brotli-decoder-out-of-bounds-write-permits-remote-code-execution-cve-2026-111497---high
  - url: >-
      https://github.com/google/brotli/commit/0ed4268a4401abcb4472096340477cf4af7d1a2b
  - url: >-
      https://github.com/google/brotli/commit/50a9b70a4d5e1443fc40927952276b68fffa83a0
  - url: >-
      https://github.com/google/brotli/commit/b418fa81c48262a86a95332b0bc6d62c30aa78b6
  - url: >-
      https://github.com/google/brotli/commit/da9806362874b9bd4b552a3af360b5d6347beb12
  - url: 'https://github.com/google/brotli/releases/tag/v1.0.10'
  - url: 'https://github.com/google/brotli/releases/tag/v1.1.1'
  - url: 'https://github.com/google/brotli/releases/tag/v1.2.1'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/brotli/PYSEC-2026-4322.yaml
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/brotlicffi/PYSEC-2026-4323.yaml
  - url: 'https://nodejs.org/en/blog/vulnerability/october-2026-security-releases'
  - url: 'https://opensourcemalware.com/blog/node2shell-affects-python'
  - url: 'https://pypi.org/project/Brotli'
  - url: 'https://pypi.org/project/brotlicffi'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-111497'
  - url: 'https://github.com/advisories/GHSA-9v8h-qqgm-4m35'
tags:
  - ghsa
  - pip
ingestedAt: '2026-10-23T19:35:13.433Z'
---

## Overview

A buffer overflow vulnerability in the Brotli decoder (c/dec/decode.c) in Google Brotli versions 1.0.3 through 1.2.0 on all platforms allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream.

Users need to update any Brotli libraries or binaries between 1.0.3 through 1.2.0 to the latest available version: 1.0.10 or 1.1.1 or 1.2.1.

## Affected packages

- `brotli >= 1.0.3, < 1.2.1`
- `brotlicffi >= 1.0.3, < 1.2.1.0`

## Remediation

Upgrade to a patched release:

- `brotli 1.2.1`
- `brotlicffi 1.2.1.0`