9.3
CRITICAL CVSS 4.0
CVE-2026-64621
FreeRDP before 3.28.0 Double-Free via selectedmonitors
Description

FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated through the settings object, and a raw non-owning pointer to it is freed on the strtoul error path without clearing settings->MonitorIds, leaving it dangling; at teardown freerdp_settings_free() frees the same buffer again. An attacker who convinces a victim to open a crafted .rdp file with oversized monitor tokens can trigger a size-controlled double-free in any FreeRDP CLI client (xfreerdp/sdl-freerdp/wlfreerdp) in the default configuration.

INFO

Published Date :

July 20, 2026, 12:19 p.m.

Last Modified :

July 20, 2026, 12:19 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-64621 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Freerdp freerdp
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update FreeRDP to version 3.28.0 or later to fix a double-free vulnerability.
  • Update FreeRDP to version 3.28.0 or later.
  • Avoid opening untrusted .rdp files.
  • Recompile FreeRDP from source code.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-64621.

URL Resource
https://github.com/FreeRDP/FreeRDP/commit/1f7a716d39b5605bb8a83b0c3c97a6ce386609ef
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-f27x-frr8-j9hc
https://www.vulncheck.com/advisories/freerdp-before-double-free-via-selectedmonitors
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-64621 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-64621 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-64621 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-64621 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 20, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'FreeRDP', 'product': 'FreeRDP', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.28.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.28.0', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}]
    Added Description FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated through the settings object, and a raw non-owning pointer to it is freed on the strtoul error path without clearing settings->MonitorIds, leaving it dangling; at teardown freerdp_settings_free() frees the same buffer again. An attacker who convinces a victim to open a crafted .rdp file with oversized monitor tokens can trigger a size-controlled double-free in any FreeRDP CLI client (xfreerdp/sdl-freerdp/wlfreerdp) in the default configuration.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H
    Added CWE CWE-415
    Added Reference https://github.com/FreeRDP/FreeRDP/commit/1f7a716d39b5605bb8a83b0c3c97a6ce386609ef
    Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-f27x-frr8-j9hc
    Added Reference https://www.vulncheck.com/advisories/freerdp-before-double-free-via-selectedmonitors
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.