CVE-2026-55648
Received Received - Intake

Integer Overflow in FreeRDP Leading to Memory Corruption

Publication date: 2026-08-19

Last updated on: 2026-08-19

Assigner: GitHub, Inc.

Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, freerdp_image_copy_from_icon_data in libfreerdp/codec/color.c calculates nWidth multiplied by nHeight multiplied by FreeRDPGetBytesPerPixel(format) in 32-bit arithmetic. A malicious RDP server can send a RAIL TS_ICON_INFO update with dimensions such as 32768 by 32768 and 32 bits per pixel so the required-size calculation wraps, bypassing the cbBitsColor source bounds check before freerdp_image_copy_no_overlap reads attacker-controlled icon data. This affects RemoteApp clients using the vulnerable library path, while xfreerdp has a caller-side mitigation. This issue is fixed in version 3.27.0.

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Meta Information

Published
2026-08-19
Last Modified
2026-08-19
Generated
2026-08-19
AI Q&A
2026-08-19
EPSS Evaluated
N/A
NVD
CVE-2026-55648
EUVD
EUVD-2026-62666

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
freerdp freerdp 3.27.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

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Executive Summary

CVE-2026-55648 is an integer overflow vulnerability in FreeRDP's freerdp_image_copy_from_icon_data function. It occurs when calculating the required buffer size for copying icon data using 32-bit arithmetic. An attacker controlling an RDP server can send a specially crafted icon update with dimensions like 32768x32768 pixels and 32 bits per pixel, causing the calculation to wrap around to zero. This bypasses bounds checks and allows out-of-bounds memory access.

Detection Guidance

Check FreeRDP version with 'xfreerdp --version' or 'freerdp2 --version'. If version is below 3.27.0, the system is vulnerable. Monitor network traffic for RDP connections with unusual icon update packets, particularly those with dimensions like 32768x32768 pixels.

Impact Analysis

If you use FreeRDP clients running in RemoteApp mode with versions prior to 3.27.0, an attacker controlling an RDP server could exploit this to corrupt memory on your system. This could lead to crashes, arbitrary code execution, or unauthorized access depending on the attacker's goals. Desktop mode users are unaffected.

Compliance Impact

This vulnerability could potentially lead to unauthorized memory access or corruption in FreeRDP clients using RAIL/Remote App mode. For compliance with standards like GDPR or HIPAA, which require strict data protection and integrity, such vulnerabilities may result in data breaches or unauthorized access to sensitive information. Organizations using vulnerable versions of FreeRDP may face compliance violations due to the risk of memory corruption and potential exposure of protected data.

Mitigation Strategies

Upgrade FreeRDP to version 3.27.0 or later immediately. If upgrading is not possible, disable RemoteApp mode or restrict RDP server connections to trusted sources. Apply network-level controls to block suspicious RDP traffic patterns.

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