Findings

CVE-2026-31883

FreeRDP is a free implementation of the Remote Desktop Protocol.

Published Mar 13, 2026 · updated Jun 17, 2026 · freerdp freerdp

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 13, 2026 · NIST NVD

    Detected

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server

  2. Jun 17, 2026 · NIST NVD

    Updated

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server

Affected

  • cpe freerdp/freerdpversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-31883

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-31883

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtr

    nvd.nist.gov

References

CVE-2026-31883 · ZeroDay Findings