Scrapy is vulnerable to a denial of service (DoS) attack due to flaws in brotli decompression implementation
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 software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | brotli | < 1.2.0 | 1.2.0 |
| Python (PyPI) | scrapy | < 2.13.4 | 2.13.4 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-6176
- https://github.com/google/brotli/issues/1327
- https://github.com/google/brotli/issues/1375
- https://github.com/google/brotli/pull/1234
- https://github.com/scrapy/scrapy/pull/7134
- https://github.com/google/brotli/commit/67d78bc41db1a0d03f2e763497748f2f69946627
- https://github.com/scrapy/scrapy/commit/14737e91edc513967f516fc839cc9c8a4f8d91da
- https://github.com/google/brotli
- https://github.com/google/brotli/releases/tag/v1.2.0
- https://huntr.com/bounties/2c26a886-5984-47ee-a421-0d5fe1344eb0
- https://pypi.org/project/scrapy
- https://github.com/advisories/GHSA-2qfp-q593-8484
- https://pypi.org/project/brotli
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-400- Platform
- Python (PyPI)
- Package
brotli, scrapy- Disclosed
- 31.10.2025
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-1906 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - PYSEC-2026-2401 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-2qfp-q593-8484 - CC BY 4.0
Vulnerability history: scrapy
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 09.2017 09.2026
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 6
- Medium 8
Disclosures per year
- 2017: 1
- 2018: 0
- 2019: 0
- 2020: 0
- 2021: 1
- 2022: 3
- 2023: 0
- 2024: 6
- 2025: 1
- 2026: 2
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Scrapy is vulnerable to a denial of service (DoS) attack due to flaws in brotli decompression implementation this entry
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