CVE-2026-121406
FreeRDP before 3.32.2 Client Denial of Service via Zero-Output ZGFX Payload
Description
FreeRDP before 3.32.2 allows a client assertion abort because rdpgfx_on_data_received rejects only negative zgfx_decompress status and passes the resulting null output pointer to Stream_StaticConstInit. A malicious RDP server can send a zero-output ZGFX payload on the RDPGFX channel after session activation to terminate the client.
INFO
Published Date :
Nov. 3, 2026, 3:17 p.m.
Last Modified :
Nov. 3, 2026, 3:59 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update FreeRDP to version 3.32.2 or later.
- Ensure RDPGFX channel is properly validated.
- Apply security patches for RDP clients.
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-2026-121406.
| URL | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2c9x-4gr7-hrwx | Vendor Advisory |
| https://www.vulncheck.com/advisories/freerdp-before-3.32.2-client-denial-of-service-via-zero-output-zgfx-payload | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121406 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-2026-121406
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-2026-121406 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121406 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.
-
Initial Analysis by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* versions up to (excluding) 3.32.2 Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2c9x-4gr7-hrwx Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/freerdp-before-3.32.2-client-denial-of-service-via-zero-output-zgfx-payload Types: Third Party Advisory -
New CVE Received by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added Description FreeRDP before 3.32.2 allows a client assertion abort because rdpgfx_on_data_received rejects only negative zgfx_decompress status and passes the resulting null output pointer to Stream_StaticConstInit. A malicious RDP server can send a zero-output ZGFX payload on the RDPGFX channel after session activation to terminate the client. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L Added CWE CWE-617 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121406.json">CVE-2026-121406</a> Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2c9x-4gr7-hrwx Added Reference https://www.vulncheck.com/advisories/freerdp-before-3.32.2-client-denial-of-service-via-zero-output-zgfx-payload