CVE-2026-67305: Security vulnerability
CVE-2026-67305 affects Windows. The flaw is described as a buffer overflow vulnerability.
What happened
0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer. A security weakness in Windows is being tracked as CVE-2026-67305. CVE-2026-67305 affects Windows.
FreeRDP Windows client before 3. A buffer overflow occurs when software writes more data into a memory area than it can safely hold. The flaw is described as a buffer overflow vulnerability.
The result can range from a crash to attacker-controlled execution when the overwritten memory influences program flow. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code executi.
Editorial note: this News Brief follows the available evidence and adds length only when additional facts or useful context are available. Where public reporting does not establish a specific victim sequence, CyberDeltaForce does not present one as fact.
What the reporting and advisory establish
FreeRDP Windows client before 3.
0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer.
A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code executi
A security weakness in Windows is being tracked as CVE-2026-67305. The flaw is described as a buffer overflow vulnerability. A buffer overflow occurs when software writes more data into a memory area than it can safely hold. The result can range from a crash to attacker-controlled execution when the overwritten memory influences program flow. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code executi. The issue currently carries a CRITICAL 9.4 severity signal in the available reporting.
What this means for your environment
Move from the published facts to the technical path, exposure conditions and defensive decisions that matter in a real environment.
Attack & Exploitation Path
The sequence below shows how the vulnerability can be reached and what successful exploitation can produce. Each stage is labeled by evidence status.
Required condition: Windows is present and the vulnerable function is reachable in the way the software is normally used.
Required condition: attacker-controlled input or the relevant workflow reaches the affected code path.
the reported buffer overflow is triggered inside Windows, crossing the security boundary described by the advisory or vulnerability record.
Not publicly disclosed in enough detail to state a specific post-exploitation result without inference.
Map Windows to real assets, verify the vendor fix or mitigation, confirm the vulnerable path is no longer reachable, and review relevant telemetry for behavior consistent with exploitation.
Why this matters to you
CVE-2026-67305 matters because the practical risk is not the score alone — it is whether Windows exists in your environment and whether the reported trigger or exposure path can reach it. The current severity is CRITICAL 9.4. No exploitation flag is currently present in the CDF data, but that does not remove the need to validate affected systems.
Does this deserve attention in my environment?
Check the conditions below against your use of Windows.
Select the conditions that are true in your environment. Leaving a condition unselected does not mean you are safe — it only means you have not marked it as applicable.
- Search endpoint, software and asset inventory for Windows.
- Confirm the vendor-recommended fixed version or mitigation and verify deployment, not just assignment, across affected assets.
- Review relevant endpoint, application, network or identity telemetry for activity associated with exploitation of the affected component.
- Track vendor and government guidance for any change in exploitation status while remediation is underway.
What remains unconfirmed
- Available reporting does not currently indicate exploitation, but that can change as vendor, government or threat-intelligence reporting develops.
Sources & References
Original reporting and technical references are kept here for readers who want to verify the facts. Publisher names stay out of the reading flow above.