Bug 2521846

Summary: CVE-2026-71265 domoticz: Domoticz: Stack Buffer Overflow via MochadTCP MOCHAD_RFSEC message processing [fedora-all]
Product: [Fedora] Fedora Reporter: Vladimir Vasilev <vvasilev>
Component: domoticzAssignee: Michael Cronenworth <mike>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: mike
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["4ce2fbf8-7b3e-492d-be63-c352450816c8"]}
Fixed In Version: Doc Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2511559    

Description Vladimir Vasilev 2026-08-24 12:42:41 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.

Domoticz's MochadTCP::MatchLine() handler for MOCHAD_RFSEC messages (hardware/MochadTCP.cpp) copies network-received data from the up-to-1028-byte m_mochadbuffer into a fixed 50-byte stack buffer tempRFSECbuf using strcpy() with no length check, across three separate code branches (DS10A/KR10A/MS10A device types). An attacker on the local network segment able to reach the Mochad TCP bridge (default port 1099, no authentication) can send a crafted packet that overflows tempRFSECbuf by up to several hundred bytes, corrupting the Domoticz worker thread's stack.