Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-63633

CVE-2026-63633HIGH

FreeRDP: Heap buffer overflow in Opus audio decode (`freerdp_dsp_decode_opus` resizes the wrong stream) — server→client

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   P   N   P   H   H   H    7.7   .0062   47.8     —

AFFECTED
  Product  Versions    Fixed
  FreeRDP  < 3.28.0 –  —

TIMELINE
  Jul 17  Reserved by GitHub_M
  Aug 19  Published (CNA: GitHub_M)
  Sep 24  EXPLOIT PUBLISHED — CVE-2026-63633 (FreeRDP). Public exploit reference added.

CWE-122 · CNA: GitHub_M · CVSS v4.0 · 4 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 17, 2026	Reserved	Reserved by GitHub_M
August 19, 2026	Published	Published (CNA: GitHub_M)
September 24, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-63633 (FreeRDP). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
FreeRDP	FreeRDP	—	< 3.28.0	—

Weaknesses

CWE-122

References (4)

https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae [Patch]
https://github.com/FreeRDP/FreeRDP/pull/12993 [Issue Tracking, Patch]
https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0 [Release Notes]
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-63633 at cve.org

Vendors: freerdp

Weaknesses: CWE-122

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-63633 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.