Bug 2494941

Summary: CVE-2026-53433 fzf: fzf: Denial of Service via inefficient HTTP body processing [fedora-all]
Product: [Fedora] Fedora Reporter: Jon Weiser <jweiser>
Component: fzfAssignee: Elliott Sales de Andrade <quantum.analyst>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: epel-packagers-sig, go-sig, quantum.analyst
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["09127cce-f5b5-441a-b777-18db2bda3539"]}
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Last Closed: 2026-08-04 03:24:06 UTC Type: ---
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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: 2494891    

Description Jon Weiser 2026-06-30 14:20:13 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.

fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service.

This issue was fixed in version 0.73.1.
Comment 1 Elliott Sales de Andrade 2026-08-04 03:24:06 UTC 
We were on 0.73.1 a month before this was filed.