FreeRDP up to 3.32.1 RDPGFX Client out-of-bounds write

Summaryinfo

A vulnerability, which was classified as critical, was found in FreeRDP up to 3.32.1. This impacts an unknown function of the component RDPGFX Client. Such manipulation leads to out-of-bounds write. This vulnerability is uniquely identified as CVE-2026-121958. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in FreeRDP up to 3.32.1 and classified as critical. Affected by this issue is some unknown functionality of the component RDPGFX Client. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

FreeRDP through 3.32.1 has a heap out-of-bounds write in the RDPGFX client because the delete_surface callback truncates surface hash keys to 16 bits, leaving the surface table inconsistent so HashTable_GetKeys writes past its allocated key array. A malicious or man-in-the-middle RDP server can exploit this by creating surfaceId 0xFFFF, closing the RDPGFX channel, sending repeated DELETESURFACE PDUs, and then sending ENDFRAME or RESETGRAPHICS.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-121958 since 11/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/04/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Remote Access Software

Name

• FreeRDP

Version

• 3.32.0
• 3.32.1

License

• open-source

Website

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

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Once again VulDB remains the best source for vulnerability data.

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