CVE-2026-67300: Security vulnerability
CVE-2026-67300 affects the affected technology. The flaw is described as a use-after-free vulnerability.
What happened
CVE-2026-67300: FreeRDP before 3 29 0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIF. 0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. A security weakness in the affected technology is being tracked as CVE-2026-67300.
CVE-2026-67300 affects the affected technology. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e. A use-after-free flaw is a memory-safety problem in which software continues using memory after it has already been released.
string, windowRects, visibilityRects, icon buffer. The flaw is described as a use-after-free vulnerability. If an attacker can influence what happens in that memory area next, the bug can corrupt the application and sometimes be turned into code execution.
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
0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled.
When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.
string, windowRects, visibilityRects, icon buffer
A security weakness in the affected technology is being tracked as CVE-2026-67300. The flaw is described as a use-after-free vulnerability. A use-after-free flaw is a memory-safety problem in which software continues using memory after it has already been released. If an attacker can influence what happens in that memory area next, the bug can corrupt the application and sometimes be turned into code execution. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e. string, windowRects, visibilityRects, icon buffer.
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: CVE-2026-67300 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 use-after-free is triggered inside the affected technology, 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 CVE-2026-67300 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-2026-67300 matters because the practical risk is not the score alone — it is whether the affected technology or service exists in your environment and whether the reported trigger or exposure path can reach it. The current severity is HIGH 7.5. 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 the affected technology or service.
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 the affected technology or service.
- 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.