Bug 2522080

Summary: CVE-2026-49855 python-pep517: Tornado: Denial of Service via uncontrolled gzip decompression memory consumption [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Ganesh <gnaik>
Component: python-pep517Assignee: Orphan Owner <extras-orphan>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: encukou, extras-orphan, python-packagers-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["9697158f-853c-4d52-8836-1cf2e536c70b"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2500686    

Description Ganesh 2026-08-24 17:07:05 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.