{"id":"CVE-2026-84366","summary":"Scrapy: S3DownloadHandler sends signed S3 requests over plaintext HTTP by default","details":"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.","aliases":["GHSA-76g3-c3x4-crvx"],"modified":"2026-09-03T03:48:18.011594073Z","published":"2026-09-01T20:29:23.143Z","database_specific":{"cwe_ids":["CWE-319"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84366.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/scrapy/scrapy/releases/tag/2.17.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84366.json"},{"type":"ADVISORY","url":"https://github.com/scrapy/scrapy/security/advisories/GHSA-76g3-c3x4-crvx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-84366"},{"type":"FIX","url":"https://github.com/scrapy/scrapy/commit/9523e1ec8c41fde265a26d14563d178b6f1ad04b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/scrapy/scrapy","events":[{"introduced":"0"},{"fixed":"9523e1ec8c41fde265a26d14563d178b6f1ad04b"},{"fixed":"feb692f552e3ed4533cf4e3af4809908d84cd763"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"2.17.0"}]}}],"versions":["2.16.0","2.15.0","2.14.1","2.14.0","2.13.0","2.12.0","2.11.0","2.10.0","2.9.0","2.8.0","2.7.1","2.7.0","2.6.1","2.6.0","1.8.0","2.5.0","2.4.0","2.3.0","2.2.0","2.1.0","2.0.0","1.7.0","1.6.0","1.5.0","1.4.0","1.3.2","1.3.1","1.2.2","1.3.0","1.2.1","1.2.0","1.2.0dev2","1.0.0rc1","scrapy-0.25.1-sc","hojo","0.25.1","0.24.0","0.25.0","0.23.0","0.21.0","0.17.0","0.15.1","0.14.0","0.15.0","0.10.3","0.10.2","0.10.1","0.10","0.10-rc1","0.9","0.9-rc1","0.8","0.7","0.7-rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84366.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}