CVE-2026-109255 FreeRDP CVE debrief

Who should care

FreeRDP users, particularly those using 32-bit clients, should assess exposure and prioritize verification of vulnerable versions. This includes operators of affected systems, platform administrators, vulnerability management teams, and security teams. They should review the vulnerability details, assess the potential impact, and plan for remediation or mitigation as needed. Verification of vulnerable FreeRDP versions is required to ensure the security of

Why it matters

FreeRDP 3.0.0 before 3.32.0 users, especially those with 32-bit clients, should assess exposure and prioritize verification and remediation due to the potential for denial of service and remote code execution.

• Denial of service due to heap buffer overflow
• Potential remote code execution on 32-bit clients
• Verification of vulnerable FreeRDP versions is required
• Remediation priority for FreeRDP 3.0.0 to 3.32.0 users

Technical summary

FreeRDP 3.0.0 before 3.32.0 contains an integer truncation vulnerability in license_check_stream_length. This allows a malicious RDP server to trigger a heap buffer overflow on 32-bit clients. The vulnerability can be exploited by sending a crafted SERVER_LICENSE_REQUEST with a large scopeCount, bypassing length checks and causing out-of-bounds writes. This can lead to denial of service or remote code execution. Users of FreeRDP 3.0.0 to 3.32.0 should assess their exposure and prioritize verification and remediation.

Defensive priority

Assess exposure and prioritize verification for FreeRDP 3.0.0 to 3.32.0 users

Recommended defensive actions

• Assess exposure for FreeRDP 3.0.0 to 3.32.0 users
• Prioritize verification of vulnerable versions
• Update to version 3.32.0 or later if vulnerable
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the integer truncation vulnerability in license_check_stream_length, allowing a malicious RDP server to trigger a heap buffer overflow on 32-bit clients.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.