CVE-2026-26955 — CVE & Security Advisory Radar

🎯 CVE-2026-26955 HIGH 8.8 🔥 EPSS 54% 🧪 PoC 🇪🇺 EUVD

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CVE-2026-26955 | FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimen

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled `cmd->left`/`cmd->top` (and subcodec rectangle offsets) to reach image copy routines that write into `surface->data` without bounds enforcement. The OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs*` pointer with attacker-controlled pixel data, and corruption of `codecs*` is sufficient to reach an indirect function pointer call (`NSC_CONTEXT.decode` at `nsc.c:500`) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.

Klassifikation & Betroffenheit:

FreeRDP FreeRDP < 3.23.0freerdp freerdp *

Improper Restriction of Operations within the Bounds of a Memory Buffer 🎯 High

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

🛡️ Empfohlene Mitigation: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow prot…

Vollständige Definition bei MITRE ➔

⚔️ Typische Angriffsmuster (CAPEC):

CAPEC-10 · Buffer Overflow via Environment Variable… (High) CAPEC-14 · Client-side Injection-induced Buffer Ove… (High) CAPEC-24 · Filter Failure through Buffer Overflow (High) CAPEC-42 · MIME Conversion (High) CAPEC-44 · Overflow Binary Resource File (Very High) CAPEC-45 · Buffer Overflow via Symbolic Links (High) CAPEC-100 · Overflow Buffers (Very High) CAPEC-123 · Buffer Manipulation (Very High)

🧩 Ähnliche Schwachstellen (Hersteller/Klasse/Score-Band):

CVE-2024-32659 9.8 CVE-2024-32658 9.8 CVE-2024-32459 9.8 CVE-2024-32458 9.8 CVE-2024-32041 9.8

🩹 Patch verfügbar (OSV):

🩹 b933ae18d9ad2a1d73c610868fcc30eb61654070 (Commit) 🩹 7d8fdce2d0ef337cb86cb37fc0c436c905e04d77 (Commit)

📚 Referenzen & Quellen:

🇪🇺 Original-Eintrag (ENISA EUVD) 🇺🇸 NVD-Eintrag

Ausnutzungs-Zeitleiste:

Reserviert 2026

Veröffentlicht 02/2026

Heute 07.09.

CVSS-Vektor-Analyse: 8.8

AV · Angriffsvektor Netzwerk

AC · Komplexität Gering

PR · Privilegien Keine

UI · Interaktion Erforderlich

S · Scope Unverändert

C · Vertraulichkeit Hoch

I · Integrität Hoch

A · Verfügbarkeit Hoch

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Veröffentlicht:25.02.2026

Aktualisiert:15.07.2026 02:19

Assigner (CNA):GitHub_M

EUVD-ID:EUVD-2026-8739

Quellen: 🇪🇺 EUVD-Datenbank (ENISA) + 🇺🇸 NVD-Anreicherung · 24-h-Cache

CWE-119: Memory Corruption ✓ Offizieller Patch / Advisory verfügbar

💡 Gegenmaßnahme: Sicherheits-Update des Herstellers zeitnah einspielen und Netzwerksegmentierung prüfen.

Tier	2026-08-29	2026-09-06
≥90 %	4	0
≥50 %	4	0
≥10 %	3	0
<10 %	304	300

8.8 HIGH

🇪🇺 EUVD

EPSS

54%

CVE-2026-26955 🌐 Netzwerk (Remote) 🔓 Keine Authentifizierung nötig

🧪 FreeRDP

CVE-2026-26955 | FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimen

CWE-119: Memory Corruption ✓ Offizieller Patch / Advisory verfügbar

💡 Gegenmaßnahme: Sicherheits-Update des Herstellers zeitnah einspielen und Netzwerksegmentierung prüfen.

25.02.2026

🛡️ Details ➔

Zero-Day & Vulnerability Intelligence Hub