VDB-354277 · CVE-2026-33986 · EUVD-2026-17233

FreeRDP up to 3.24.1 libfreerdp/codec/h264.c yuv_ensure_buffer heap-based overflow

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.1	$0-$5k	0.00

Summaryinfo

A vulnerability was found in FreeRDP up to 3.24.1. It has been rated as critical. Affected by this vulnerability is the function yuv_ensure_buffer of the file libfreerdp/codec/h264.c. This manipulation causes heap-based overflow. This vulnerability is tracked as CVE-2026-33986. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical was found in FreeRDP up to 3.24.1. Affected by this vulnerability is the function yuv_ensure_buffer of the file libfreerdp/codec/h264.c. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is 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(). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in yuv_ensure_buffer() in libfreerdp/codec/h264.c, h264->width and h264->height are updated before the reallocation loop. If any winpr_aligned_recalloc() call fails, the function returns FALSE but width/height are already inflated. This issue has been patched in version 3.24.2.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-33986 since 03/24/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 3.24.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-17233). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Remote Access Software

Name

FreeRDP

Version

License

open-source

Website

Product: https://github.com/FreeRDP/FreeRDP/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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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: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: FreeRDP 3.24.2

Timelineinfo

03/24/2026 CVE reserved
03/30/2026 +6 days VulDB entry created
03/31/2026 +0 days Advisory disclosed
03/31/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-33986 (🔒)
GCVE (CVE): GCVE-0-2026-33986
GCVE (VulDB): GCVE-100-354277
EUVD: 🔒

Entryinfo

Created: 03/31/2026 00:20
Updated: 03/31/2026 02:30
Changes: 03/31/2026 00:20 (65), 03/31/2026 02:30 (1)
Complete: 🔍
Cache ID: 216:B5F:103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.