Bug 2561005

Summary: CVE-2026-93753 cachelib: deepmerge: Prototype Poisoning via mergeObject function [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Joel Chamberlain <jochambe>
Component: cachelibAssignee: Michel Lind <michel>
Status: CLOSED NOTABUG QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: michel
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["c0e4fe48-e5c9-46cf-88fc-b54deca0dc5f"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
Last Closed: 2026-11-10 21:48:31 UTC Type: ---
Regression: --- Mount 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: 2529580, 2538136    

Description Joel Chamberlain 2026-10-26 18:54:56 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.

deepmerge through 4.3.1 contains a prototype poisoning vulnerability in the mergeObject() function that fails to properly validate keys being written to target objects. Attackers can supply malicious source objects in merge operations to inject attacker-controlled properties into the returned object's prototype, causing applications to inherit unintended values when accessing properties without own-property checks.
Comment 1 Michel Lind 2026-11-10 21:48:31 UTC 
This CVE record was rejected by its CNA (NVD status Rejected: withdrawn); there is no vulnerability to fix.