CVE-2026-56297 PUBLISHED

FreeRDP - Use-After-Free via Race Condition in DRDYNVC Channel Callback

Assigner: VulnCheck
Reserved: 20.06.2026 Published: 08.07.2026 Updated: 08.07.2026

FreeRDP before 3.22.0 contains a use-after-free vulnerability in dvcman_channel_close and dvcman_call_on_receive due to improper synchronization of channel_callback access. A malicious RDP server can trigger a race condition by sending DYNVC_DATA and DYNVC_CLOSE messages concurrently, causing heap-use-after-free in the drdynvc client thread and potentially enabling remote code execution or denial of service.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	High	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
CVSS Score: 7

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	FreeRDP
Product	FreeRDP
Versions	Default: unaffected affected from 0 to 3.22.0 (excl.) Version 3.22.0 is unaffected

Credits

jeremylaratro reporter

References

Problem Types

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') CWE