---
id: CVE-2025-6176
aliases:
  - GHSA-2qfp-q593-8484
  - PYSEC-2026-1906
  - PYSEC-2026-2401
title: >-
  Scrapy is vulnerable to a denial of service (DoS) attack due to flaws in
  brotli decompression implementation
summary: >-
  Scrapy is vulnerable to a denial of service (DoS) attack due to flaws in
  brotli decompression implementation
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: brotli
product: brotli
ecosystem: pip
affected:
  - brotli < 1.2.0
  - scrapy < 2.13.4
patched:
  - brotli 1.2.0
  - scrapy 2.13.4
published: '2025-10-31'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:29.153413546Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-2qfp-q593-8484'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-6176'
  - url: 'https://github.com/google/brotli/issues/1327'
  - url: 'https://github.com/google/brotli/issues/1375'
  - url: 'https://github.com/google/brotli/pull/1234'
  - url: 'https://github.com/scrapy/scrapy/pull/7134'
  - url: >-
      https://github.com/google/brotli/commit/67d78bc41db1a0d03f2e763497748f2f69946627
  - url: >-
      https://github.com/scrapy/scrapy/commit/14737e91edc513967f516fc839cc9c8a4f8d91da
  - url: 'https://github.com/google/brotli'
  - url: 'https://github.com/google/brotli/releases/tag/v1.2.0'
  - url: 'https://huntr.com/bounties/2c26a886-5984-47ee-a421-0d5fe1344eb0'
tags:
  - osv
  - pip
epss: 0.00502
epssPercentile: 0.40302
ingestedAt: '2026-07-08T18:25:44.599Z'
---

## Overview

Scrapy versions up to 2.13.3 are vulnerable to a denial of service (DoS) attack due to a flaw in its brotli decompression implementation. The protection mechanism against decompression bombs fails to mitigate the brotli variant, allowing remote servers to crash clients with less than 80GB of available memory. This occurs because brotli can achieve extremely high compression ratios for zero-filled data, leading to excessive memory consumption during decompression. Mitigation for this vulnerability needs security enhancement added in brotli v1.2.0.

## Affected packages

- `brotli < 1.2.0`
- `scrapy < 2.13.4`

## Remediation

Upgrade to a patched release:

- `brotli 1.2.0`
- `scrapy 2.13.4`