Denial of Service Vulnerability in FreeRDP's Shadow Server
CVE-2026-121404

7.1HIGH

Key Information:

Vendor

Freerdp

Status
Freerdp
Vendor
CVE Published:
3 November 2026

What is CVE-2026-121404?

FreeRDP prior to version 3.32.2 suffers from a denial of service vulnerability within its shadow server component. This flaw allows authenticated RDP clients to exploit the server by sending zero-length drdynvc DATA PDUs. Specifically, attackers can send empty messages over opened audio or rdpgfx channels, causing the FreeRDP_WTSVirtualChannelRead function to be unable to process these messages. Consequently, this results in excessive CPU consumption as threads are spun up indefinitely until the connection is terminated.

Affected Version(s)

FreeRDP 0 < 3.32.2

FreeRDP 3.32.2

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GH...
vendor-advisory
https://www.vulncheck.com/advisories/freerdp-before-3.32....
third-party-advisory

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Kushalkhemka
mayank-jangid-moon
skigeek16
opensec-intelligence
.