Scrapy up to 2.16.x S3DownloadHandler s3.py is_secure missing encryption

Summaryinfo

A vulnerability has been found in Scrapy up to 2.16.x and classified as problematic. This affects an unknown function of the file scrapy/core/downloader/handlers/s3.py of the component S3DownloadHandler. Performing a manipulation of the argument is_secure results in missing encryption. This vulnerability is identified as CVE-2026-84366. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Scrapy up to 2.16.x. This affects an unknown part of the file scrapy/core/downloader/handlers/s3.py of the component S3DownloadHandler. The manipulation of the argument is_secure with an unknown input leads to a missing encryption vulnerability. CWE is classifying the issue as CWE-311. The product does not encrypt sensitive or critical information before storage or transmission. This is going to have an impact on confidentiality. The summary by CVE is:

Scrapy is a high-level web crawling and scraping framework for Python. Prior to 2.17.0, in scrapy/core/downloader/handlers/s3.py, Scrapy's S3DownloadHandler converts an S3-scheme bucket and key request into a plaintext HTTP request to the corresponding S3 endpoint unless request.meta["is_secure"] is explicitly enabled, then signs and sends the plaintext request with configured AWS credentials. A network attacker who can observe traffic between Scrapy and S3 can read the bucket and key path, AWS Authorization header, X-Amz-Security-Token when temporary credentials are used, S3 object contents, and S3 response headers. An active man-in-the-middle attacker can also modify the plaintext S3 response body, status code, and headers before Scrapy processes them, causing scraped-data poisoning, poisoned exports, HTTP cache poisoning when caching is enabled, or influence over later crawl targets through forged redirects or attacker-controlled links. Users making S3-scheme requests with AWS credentials are affected. This issue is fixed in version 2.17.0.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-84366 since 09/01/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1600 according to MITRE ATT&CK.

Upgrading to version 2.17.0 eliminates this vulnerability.

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Productinfo

Name

• Scrapy

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16

Website

• Product: https://github.com/scrapy/scrapy/

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