Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%

Buy Us a Coffee

CVE-2026-121404— FreeRDP before 3.32.2 Shadow Server CPU Exhaustion via Zero-Length DVC DATA

Quick assessment

Affected

FreeRDP FreeRDP

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

FreeRDP 3.32.2 之前的版本在阴影服务器（shadow server）中存在一个拒绝服务（DoS）漏洞。该漏洞允许已认证的 RDP 客户端通过发送长度为 0 的 drdynvc 数据协议数据单元（DATA PDUs），使服务器线程陷入空转。攻击者可以在已打开的 audin 或 rdpgfx 通道上发送空 DATA 消息，导致 FreeRDP_WTSVirtualChannelRead 函数无法消费这些消息，从而持续占用完整的 CPU 核心资源，直至连接断开。

CVSS 6.5 · Medium Updated Nov 03, 2026

Possible ATT&CK Techniques 1 AI

T1499.005

Get alerts for future matching vulnerabilities Log in to subscribe

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!

View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title

FreeRDP before 3.32.2 Shadow Server CPU Exhaustion via Zero-Length DVC DATA

Source: CVE Program / CVE List V5

Vulnerability Description

FreeRDP before 3.32.2 contains a denial of service vulnerability in the shadow server that allows authenticated RDP clients to spin server threads by sending zero-length drdynvc DATA PDUs. Attackers can send empty DATA messages on opened audin or rdpgfx channels, so that FreeRDP_WTSVirtualChannelRead never consumes them, consuming full CPU cores until disconnect.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

未加控制的资源消耗(资源穷尽)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
FreeRDP	FreeRDP	0 ~ 3.32.2	-

II. Public POCs for CVE-2026-121404

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-121404

请登录查看更多情报信息。

Other References for CVE-2026-121404 (2)

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-fqcj-rwww-2498 vendor-advisory
https://www.vulncheck.com/advisories/freerdp-before-3.32.2-shadow-server-cpu-exhaustion-via-zero-length-dvc-data third-party-advisory

https://www.cve.org/CVERecord?id=CVE-2026-121404

Same Patch Batch · FreeRDP · 2026-11-03 · 27 CVEs total

CVE-2026-121386	7.5 HIGH	FreeRDP before 3.32.2 Denial of Service via WinPR PNG/JPEG Image Readers
CVE-2026-121392	7.4 HIGH	FreeRDP before 3.32.2 Certificate Identity Validation Bypass via tls_verify_certificate
CVE-2026-121395	6.5 MEDIUM	FreeRDP 3.17.0 before 3.32.2 Denial of Service via RemoteFX Decoder
CVE-2026-121400	6.5 MEDIUM	FreeRDP before 3.32.2 CPU Exhaustion via RDG Control Packet
CVE-2026-121412	6.5 MEDIUM	FreeRDP 3.0.0 before 3.32.2 Proxy Memory Exhaustion via DVC Reassembly
CVE-2026-121407	6.5 MEDIUM	FreeRDP before 3.32.2 Shadow Server Denial of Service via remdesk Channel
CVE-2026-121393	6.5 MEDIUM	FreeRDP 3.0.0 before 3.32.2 Denial of Service via RemoteFX Region Assertion
CVE-2026-121402	6.5 MEDIUM	FreeRDP before 3.32.2 X11 Client Crash via Zero-Width RDPGFX ResetGraphics
CVE-2026-121394	6.5 MEDIUM	FreeRDP before 3.32.2 Denial of Service via RemoteFX RLGR decoder
CVE-2026-121388	6.5 MEDIUM	FreeRDP 3.0.0 before 3.32.2 Uncapped Memory Allocation via DRDYNVC DATA_FIRST
CVE-2026-121409	5.9 MEDIUM	FreeRDP before 3.32.2 Denial of Service via Oversized X.224 Routing Token
CVE-2026-121398	5.9 MEDIUM	FreeRDP before 3.32.2 Use-After-Free via dyn-channel-dump Module
CVE-2026-121408	5.3 MEDIUM	FreeRDP before 3.32.2 Use-After-Free via USB Redirection Control Channel
CVE-2026-121390	4.3 MEDIUM	FreeRDP before 3.32.2 Null Pointer Crash via ARM Gateway Response
CVE-2026-121396	4.3 MEDIUM	FreeRDP 3.0.0 before 3.32.2 denial of service via RTS padding assertion
CVE-2026-121391	4.3 MEDIUM	FreeRDP before 3.32.2 File Descriptor Exhaustion via Parallel CREATE
CVE-2026-121399	4.3 MEDIUM	FreeRDP before 3.32.2 Memory Exhaustion via RD Gateway Packet Length
CVE-2026-121410	4.3 MEDIUM	FreeRDP before 3.32.2 Denial of Service via RDPGFX ALPHA WIRETOSURFACE_2
CVE-2026-121397	4.3 MEDIUM	FreeRDP before 3.32.2 Heap Over-Read via WinPR save_png_to_buffer()
CVE-2026-121403	4.3 MEDIUM	FreeRDP before 3.32.2 Denial of Service via Malformed Drive IRP

Showing top 20 of 27 CVEs. View all on vendor page → →

IV. Related Vulnerabilities

Same product: FreeRDP

Same vendor: FreeRDP

Same weakness: CWE-400