Bug 2498474

Summary: CVE-2026-59868 fcitx5: js-yaml: Denial of Service via quadratic CPU time parsing with merge keys [fedora-all]
Product: [Fedora] Fedora Reporter: jkelly <jkelly>
Component: fcitx5Assignee: Qiyu Yan <yanqiyu01>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: 45CC: yanqiyu01
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["479ee886-86cf-4de4-8147-778d611b8b8e"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2498114    

Description jkelly 2026-07-09 11:08:13 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.

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in version 5.2.0.
Comment 1 Aoife Moloney 2026-08-17 15:16:10 UTC 
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.