Bug 2550500 (CVE-2026-109939)

Summary: CVE-2026-109939 freerdp: FreeRDP 3.27.1 before 3.32.0 NULL Pointer Dereference via Cache Bitmap V3 Order
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in FreeRDP. A malicious or compromised Remote Desktop Protocol (RDP) server can cause a Denial of Service (DoS) by crashing the client application during connection establishment. By sending a specially crafted bitmap cache order before connection initialization completes, the server triggers a null pointer dereference in the client parser. This issue prevents users from establishing remote desktop connections when bitmap caching features are enabled.
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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: 2560923    
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Description OSIDB Bzimport 2026-10-13 13:44:03 UTC 
FreeRDP 3.27.1 before 3.32.0 contains a NULL pointer dereference in update_read_cache_bitmap_v3_order() in libfreerdp/core/orders.c, which accesses the client bitmap cache when the CBR3_DO_NOT_CACHE flag is set, even though the cache is not yet initialized before Demand Active. A malicious or compromised RDP server can send a Cache Bitmap V3 order during connection setup to crash a connecting client that has enabled the non-default Bitmap Cache V3 feature (/cache:codec:<rfx|nsc|jpeg>).