Bug 2500686 (CVE-2026-49855) - CVE-2026-49855 tornado: Tornado: Denial of Service via uncontrolled gzip decompression memory consumption
Summary: CVE-2026-49855 tornado: Tornado: Denial of Service via uncontrolled gzip deco...
Keywords:
Status: NEW
Alias: CVE-2026-49855
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2522080 2522081 2522082
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-14 21:05 UTC by OSIDB Bzimport
Modified: 2026-10-12 11:14 UTC (History)
49 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:67146 0 None None None 2026-09-14 13:38:14 UTC
Red Hat Product Errata RHSA-2026:67147 0 None None None 2026-09-14 13:33:50 UTC
Red Hat Product Errata RHSA-2026:80741 0 None None None 2026-10-12 11:14:47 UTC

Description OSIDB Bzimport 2026-07-14 21:05:08 UTC 
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.
Comment 2 Jon Orris 2026-09-14 13:33:47 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:67147 https://access.redhat.com/errata/RHSA-2026:67147
Comment 3 Jon Orris 2026-09-14 13:38:10 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:67146 https://access.redhat.com/errata/RHSA-2026:67146
Comment 4 Jon Orris 2026-10-12 11:14:44 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:80741 https://access.redhat.com/errata/RHSA-2026:80741
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