CVE-2026-57156 FreeRDP CVE debrief

Who should care

Users of FreeRDP clients on 32-bit builds prior to version 3.28.0 should update to the latest version to prevent potential exploitation. This includes administrators and operators responsible for managing and maintaining FreeRDP clients in their environments. Additionally, security teams and vulnerability management teams should be aware of this vulnerability and prioritize patching or mitigation efforts.

Technical summary

The vulnerability exists in the update_read_delta_points function in libfreerdp/core/orders.c. An integer overflow occurs when an attacker-controlled point count is multiplied by sizeof(DELTA_POINT), allowing a malicious RDP peer to allocate an undersized heap buffer and write beyond it during initialization. This issue affects FreeRDP clients on 32-bit builds prior to version 3.28.0. The vulnerability can be triggered by a malicious RDP peer, and it may allow for remote code execution or denial of service.

Defensive priority

High

Recommended defensive actions

• Update FreeRDP clients to version 3.28.0 or later
• Restrict access to RDP services
• Monitor for suspicious RDP activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-10T20:16:48.257Z and has not been modified since then. The NVD entry is currently 8.6 HIGH. This information is based on the CVE.org and NVD records. However, the impact and affected scope may need further verification by defenders. FreeRDP clients on 32-bit builds prior to version 3.28.0 are potentially affected. The vulnerability exists in the update_read_delta_points function in libfreerdp/core/orders.c. An integer overflow occurs when an attacker-controlled point count is multiplied by sizeof(DELTA_POINT), allowing a malicious RDP peer to allocate an undersized heap buffer and write beyond it during initialization.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.