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Advisory severityMedium5.6Red Hat Linux

Medium [CVE-2026-56297] Remote code execution or denial of service via use-after-free race condition

This medium-severity Red Hat Linux advisory covers CVE-2026-56297 affecting Red Hat Enterprise Linux 6, Red Hat package: freerdp.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-56297 Source published Source updated

VulniPulse record published Record updated

CVE-2026-56297
Affected products & platforms
Red Hat LinuxRed Hat Enterprise Linux
Open source advisory

Summary

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. A flaw was found in FreeRDP.

A malicious Remote Desktop Protocol (RDP) server can exploit a use-after-free vulnerability due to improper synchronization of channel callback access. This Moderate impact flaw in FreeRDP allows a malicious RDP server to trigger a use-after-free condition on the client by exploiting a race condition during dynamic virtual channel closure.

Red Hat severity: Moderate — CVSS 5.6 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L). Weakness: CWE-364.

Affected Red Hat products: Red Hat Enterprise Linux 6. Will not fix / out of support: Red Hat Enterprise Linux 6.

Red Hat does not currently list a fixing RHSA for this CVE.

Affected products named by the advisory: Red Hat package: freerdp.

Is CVE-2026-56297 exploited?

No exploitation is reported in the sources VulniPulse tracks: CVE-2026-56297 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.

How do I fix CVE-2026-56297?

The advisory VulniPulse tracks names no fixed release. Follow Red Hat's guidance for workarounds and updates.

Confirm against the vendor advisory before you patch.

Affected versions
  • < 3.22.0

Official advisory · high-confidence parse· fetched 11 days ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.

Official advisory · high-confidence parse· fetched 11 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation
  • Configure host-based firewalls (e.g., firewalld) or network egress filtering so that the workstation can only initiate outbound RDP connections (typically TCP 3389) to known, trusted internal RDP gateways or corporate servers. Blocking outbound RDP to the wider internet neutralizes the threat of users accidentally connecting to malicious external endpoints.

Official advisory · high-confidence parse· fetched 11 days ago·verify at source

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