CVE-2026-63633CWE-122

CVE-2026-63633

Critical · published August 19, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
49.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
7.7 · 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
EPSS
0.00619 · 49.0th percentile
Weakness
CWE-122 · Heap-based Buffer Overflow
Published
2026-08-19T22:17Z
Affected products (1)
ProductVersionsFixed in
freerdp/freerdp< 3.28.03.28.0
References (4)
https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae · [email protected]https://github.com/FreeRDP/FreeRDP/pull/12993 · [email protected]https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0 · [email protected]https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq · [email protected]
EPSS history
Timeline
  • 19 AUG 18:00Z
    FreeRDP: Heap buffer overflow in Opus audio decode (`freerdp_dsp_decode_opus` resizes the wrong stream) — server→client
    cvelistv5