CVE-2025-6176: Brotli decompression bomb DoS in scrapy/scrapy
Brotli versions up to 1.1.0 are vulnerable to a denial of service (DoS) attack due to decompression. This issue has been patched in Brotli version 1.2.0.
Additionally, this affects users who implement the Brotli decompression with Scrapy versions up to 2.13.2, leaving them vulnerable to a denial of service (DoS) attack. 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.
Other sources
Scrapy versions up to 2.13.2 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.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-6176?
CVE-2025-6176 has a high severity due to the potential for denial of service attacks.
How do I fix CVE-2025-6176?
To fix CVE-2025-6176, upgrade Scrapy to version 2.14.0 or later, where the vulnerability has been addressed.
Which versions of Scrapy are affected by CVE-2025-6176?
Scrapy versions up to and including 2.13.2 are affected by CVE-2025-6176.
What type of attack does CVE-2025-6176 enable?
CVE-2025-6176 enables a denial of service (DoS) attack due to a flaw in brotli decompression.
Who is impacted by CVE-2025-6176?
Developers and users of Scrapy versions up to 2.13.2 are impacted by CVE-2025-6176.