Bug 2500040 (CVE-2026-62643)

Summary: CVE-2026-62643 roundcubemail: Roundcube Webmail: Server-Side Request Forgery via insufficient CSS sanitization
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Roundcube Webmail. Insufficient sanitization of Cascading Style Sheets (CSS) within HTML email messages allows a remote attacker to perform Server-Side Request Forgery (SSRF) or disclose sensitive information. This vulnerability occurs when stylesheet links point to local network hosts, potentially enabling access to internal resources or sensitive data. This issue is a result of incomplete fixes for previously identified vulnerabilities.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2500072, 2500073    
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Description OSIDB Bzimport 2026-07-14 17:01:36 UTC
In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. NOTE: this issue exists because of insufficient fixes for CVE-2026-35540 and CVE-2026-48843.