---
cve: "CVE-2026-55191"
severity: "HIGH"
cvss: 8.7
epss: "63%"
vendor: "FreeRDP"
kev: false
exploited: false
published: "2026-08-19 17:44:52"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T09:52:43+02:00"
---

# CVE-2026-55191

> 8.7 HIGH · 🧪 PoC

## Beschreibung

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients that negotiate RDPGFX AVC444 with an H.264 decoder backend calculate the intermediate YUV444 allocation size in libfreerdp/codec/h264.c with 32-bit multiplication in avc444_ensure_buffer. A malicious RDP server can supply surface dimensions for which piDstStride multiplied by padDstHeight wraps to a small nonzero value, causing winpr_aligned_recalloc to allocate an undersized buffer before YUV420CombineToYUV444 writes using the actual stride and rectangle dimensions. This can cause a client crash and may permit code execution through attacker-influenced heap corruption. This issue is fixed in version 3.27.0.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/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)

- 97f40b9e766af375f4e41ac6a3f4397d708d249c (Commit)
- 4f72b0979892352ff501e84d99832dc3bdc86a53 (Commit)

## Referenzen

- <https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr>
- <https://github.com/FreeRDP/FreeRDP/pull/12873>
- <https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c>
- <https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-55191) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_