Bug 2510917

Summary: CVE-2026-67298 freerdp2: FreeRDP: Denial of Service via integer underflow in RAIL channel handling [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Srikanth Balasubramanian <sbalasub>
Component: freerdp2Assignee: Neal Gompa <ngompa13>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: negativo17, ngompa13, oholy, tdawson
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["81ad3b1f-607d-481a-828a-f233807e137f"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2510041    

Description Srikanth Balasubramanian 2026-08-04 09:38:57 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.

FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.