Bug 2507855

Summary: CVE-2026-53666 cachelib: React Router: Information disclosure via client-side constructor execution [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Ganesh <gnaik>
Component: cachelibAssignee: Michel Lind <michel>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: epel10CC: michel
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["ea3d934b-dd03-44fe-b1f8-c366d4438449"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
Last Closed: 2026-08-04 17:25:08 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: 2443016, 2507839    

Description Ganesh 2026-07-28 04:08:20 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.

React Router is a router for React. In versions 6.4.0 through 7.17.0, if application code was written in a way that allows attacker-supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for an attacker to trigger unexpected constructor execution on the client, which would in turn trigger an outbound network request. This is only possible with very specific (and unlikely) application-layer code. Note that this does not impact an application if it is using Declarative Mode. It only impacts Framework Mode and Data Mode applications that perform manual SSR/hydration. This issue has been fixed in version 7.18.0.
Comment 1 Michel Lind 2026-08-04 17:25:08 UTC 
This CVE is in a JavaScript/NodeJS package; the JavaScript here is not shipped in the binary RPMs.