Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.
Published: 2026-08-19
Score: 7.7 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Wed, 19 Aug 2026 18:15:00 +0000

Type Values Removed Values Added
Description FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.
Title FreeRDP: Heap buffer overflow in Opus audio decode (`freerdp_dsp_decode_opus` resizes the wrong stream) — server→client
Weaknesses CWE-122
References
Metrics cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-19T18:00:52.230Z

Reserved: 2026-07-17T14:11:15.482Z

Link: CVE-2026-63633

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-19T18:17:10.017

Modified: 2026-08-19T18:17:10.017

Link: CVE-2026-63633

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-122

    Heap-based Buffer Overflow