---
cve: "CVE-2026-63633"
severity: "HIGH"
cvss: 7.7
epss: "47%"
vendor: "FreeRDP"
kev: false
exploited: false
published: "2026-08-19 18:17:10"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T05:39:39+02:00"
---

# CVE-2026-63633

> 7.7 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |

## Patch verfügbar (OSV)

- 0ed1f95d36913581cf31124f94eb5843d4263eae (Commit)
- 5370fb26fbf034ecd11d3026b6ad639b5fff493f (Commit)

## Referenzen

- <https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq>
- <https://github.com/FreeRDP/FreeRDP/pull/12993>
- <https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae>
- <https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63633) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_