FreeRDP up to 3.28.x Async Update Message Proxy update_message_WindowIcon iconInfo use after free

Summaryinfo

A vulnerability was found in FreeRDP up to 3.28.x and classified as critical. This vulnerability affects the function update_message_WindowIcon of the component Async Update Message Proxy. Such manipulation of the argument iconInfo leads to use after free. This vulnerability is documented as CVE-2026-67299. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in FreeRDP up to 3.28.x. Affected by this issue is the function update_message_WindowIcon of the component Async Update Message Proxy. The manipulation of the argument iconInfo with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with the parser-owned windowIcon->iconInfo pointer. After the parser callback returns, update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption and client crash.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-67299 since 07/29/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

Upgrading to version 3.29.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-51820). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Remote Access Software

Name

• FreeRDP

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.15
• 3.16
• 3.17
• 3.18
• 3.19
• 3.20
• 3.21
• 3.22
• 3.23
• 3.24
• 3.25
• 3.26
• 3.27
• 3.28

License

• open-source

Website

• Product: https://github.com/FreeRDP/FreeRDP/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion