FreeRDP up to 3.25.x gdi_CacheToSurface heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in FreeRDP up to 3.25.x. Affected by this issue is the function gdi_CacheToSurface. The manipulation results in heap-based overflow. This vulnerability is reported as CVE-2026-40033. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in FreeRDP up to 3.25.x. Affected is the function gdi_CacheToSurface. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-40033 since 04/08/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 323073 (SUSE SLES16: freerdp / freerdp-devel / freerdp-proxy / freerdp-proxy-plugins / etc (SUSE-SU-2026:22194-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.26.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (323073) and CERT Bund (WID-SEC-2026-1470). Once again VulDB remains the best source for vulnerability data.

Affected

  • Open Source FreeRDP

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 323073
Nessus Name: SUSE SLES16: freerdp / freerdp-devel / freerdp-proxy / freerdp-proxy-plugins / etc (SUSE-SU-2026:22194-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: FreeRDP 3.26.0

Timelineinfo

04/08/2026 CVE reserved
05/26/2026 +48 days Advisory disclosed
05/26/2026 +0 days VulDB entry created
06/27/2026 +32 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-40033 (🔒)
GCVE (CVE): GCVE-0-2026-40033
GCVE (VulDB): GCVE-100-365652
CERT Bund: WID-SEC-2026-1470 - FreeRDP: Mehrere Schwachstellen

Entryinfo

Created: 05/26/2026 17:22
Updated: 06/27/2026 21:29
Changes: 05/26/2026 17:22 (76), 05/27/2026 10:00 (7), 06/27/2026 21:29 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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