CVE-2026-109247 FreeRDP CVE debrief

Who should care

Defenders responsible for FreeRDP deployments should assess exposure and prioritize verification and remediation efforts. This includes reviewing and updating affected systems, restricting access to RDP servers, and monitoring for suspicious behavior. Security teams should also verify FreeRDP versions and ensure that compensating controls are in place for exposed systems.

Why it matters

Defenders should care about CVE-2026-109247 because it allows a malicious RDP server to potentially access arbitrary local files on the client-side through clipboard manipulation, impacting confidentiality and requiring immediate attention to verify and remediate affected FreeRDP deployments.

• Potential unauthorized access to local files
• Possible data breaches through clipboard exploitation
• Need for verification of FreeRDP versions and RDP server access controls
• Potential for malicious RDP servers to manipulate clipboard content

Technical summary

The vulnerability exists in convert_filedescriptors_to_file_list() in winpr/libwinpr/clipboard/synthetic_file.c, where server-supplied cFileName values from FileGroupDescriptorW clipboard data are concatenated into the published local file:// URI without rejecting '/' or '..' sequences. This allows a malicious RDP server to supply '../' sequences, enabling the user's next clipboard paste to copy an arbitrary local file readable by the client user instead of the expected remote file. The vulnerability impacts confidentiality and requires immediate attention.

Defensive priority

Defenders should prioritize verifying FreeRDP versions and restricting access to RDP servers.

Recommended defensive actions

• Verify FreeRDP versions and upgrade to 3.32.0 or later
• Restrict access to RDP servers
• Monitor clipboard activity for suspicious behavior
• 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 vulnerability is located in convert_filedescriptors_to_file_list() in winpr/libwinpr/clipboard/synthetic_file.c. The CVE Program record and NVD vulnerability detail provide official information. Evidence limits are based on available source details, and defenders should verify affected scope and severity with official advisories. The vulnerability allows a malicious RDP server to potentially access arbitrary local files on the client-side through clipboard manipulation.

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.