Improper handling of highly compressed data in scrapy - #VU162977
Published: November 9, 2026
Vulnerability identifier: #VU162977
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-409
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated remote attacker to cause denial of service in a Scrapy crawler through excessive CPU and memory usage.
The vulnerability exists due to unbounded decoding of chained content codings by Scrapy's HttpCompressionMiddleware when processing a response with a Content-Encoding header. An unauthenticated remote attacker can serve a response from a server the crawler visits with thousands of chained codings and a repeatedly compressed body, forcing repeated decompression.
Affected software
scrapy
Remediation
Install security update from vendor's website.
scrapy - update to 2.20.0