Bug 2547337 - CVE-2026-103262 python-flit: Tornado: Denial of Service via decompression bomb in CurlAsyncHTTPClient [fedora-all]
Summary: CVE-2026-103262 python-flit: Tornado: Denial of Service via decompression bom...
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: python-flit
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Maxwell G
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["69f12751-9ff1-40bb-82ca-1...
Depends On:
Blocks: CVE-2026-103262
TreeView+ depends on / blocked
 
Reported: 2026-10-07 09:30 UTC by jkelly
Modified: 2026-10-09 19:04 UTC (History)
4 users (show)

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


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Description jkelly 2026-10-07 09:30:12 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 versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits, causing the application process to be killed by out-of-memory conditions.

Comment 1 Tomas Hoger 2026-10-09 19:04:31 UTC
This issue was filed because flit claims to bundle tornado via bundled() Provides:

Provides:       bundled(python3dist(tornado))

According to the .spec file comment, this was added because of single log.py file from the tornado project used in flit.  I think this bundled() Provides does more harm than benefit here.  If you want to avoid bugs opened in the future for torando CVEs, consider dropping that provide.


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