Bug 2548165

Summary: CVE-2026-93600 trunk: rustls-webpki: URI Name Constraint Bypass via X.509 Certificate Misissue [fedora-all]
Product: [Fedora] Fedora Reporter: Ganesh <gnaik>
Component: trunkAssignee: Jens Reimann <jreimann>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: rawhideCC: jreimann, rust-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["ab1878dc-6ee9-4241-bf74-8bb913187643"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2538296    

Description Ganesh 2026-10-08 18:49:13 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.

rustls-webpki (rustls/webpki) versions 0.101.0 through 0.103.11 and 0.104.0-alpha releases before 0.104.0-alpha.6 ignore X.509 name constraints that apply to URI names, causing such constraints to be accepted rather than enforced. Because name constraints are restrictions on otherwise properly issued certificates, the flaw is only reachable after successful signature verification and requires a misissued certificate to exploit; the library also provides no API for asserting URI names, and URI name constraints are otherwise unimplemented. Versions 0.103.12 and 0.104.0-alpha.6 reject URI name constraints unconditionally.