CVE-2026-33983
FreeRDP: Progressive Codec Quant BYTE Underflow - UB + CPU DoS
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2.
INFO
Published Date :
March 30, 2026, 10:16 p.m.
Last Modified :
April 1, 2026, 8:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update FreeRDP to version 3.24.2.
- Apply the security patch for FreeRDP.
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-2026-33983.
| URL | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425 | Patch |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4gfm-4p52-h478 | Patch Vendor 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-2026-33983 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-2026-33983
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-2026-33983 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33983 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]
Apr. 01, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* versions up to (excluding) 3.24.2 Added Reference Type GitHub, Inc.: https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4gfm-4p52-h478 Types: Patch, Vendor Advisory -
New CVE Received by [email protected]
Mar. 30, 2026
Action Type Old Value New Value Added Description FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-190 Added CWE CWE-252 Added Reference https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425 Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4gfm-4p52-h478