CVE-2026-109252 FreeRDP CVE debrief

Who should care

Defenders responsible for configuring and maintaining FreeRDP clients should assess exposure and prioritize patching to prevent potential crashes. This includes operators managing affected platforms, vulnerability management teams, and security teams responsible for client security.

Why it matters

Defenders should care about this vulnerability because it allows malicious servers to crash FreeRDP clients, potentially leading to denial-of-service attacks. Verification of client configurations and patch levels is necessary to prevent exposure.

• Client crashes due to NULL pointer dereference
• Potential for denial-of-service attacks
• Need for verification of client configurations and patch levels

Technical summary

The vulnerability exists in the RDPEAR NDR reader of FreeRDP from version 3.9.0 before 3.32.0. A malicious server can crash a client by sending a CreateApReqAuthenticatorReq with NameCount of two or more ending before the Names pointer, causing cleanup to dereference a null base and terminate the client. This allows malicious servers to crash clients via truncated KERB_RPC_INTERNAL_NAME data. Attackers can send a CreateApReqAuthenticatorReq with NameCount of two or more ending before the Names pointer, causing cleanup to dereference a null base and terminate the client.

Defensive priority

Defenders should prioritize verifying client configurations and applying patches to prevent potential crashes.

Recommended defensive actions

• Verify client configurations to ensure they are up-to-date
• Apply patches to prevent potential crashes
• Monitor client activity for suspicious behavior
• 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 Program record and NVD vulnerability detail provide official information about the vulnerability. Vendor advisories and third-party advisories offer additional context. The vulnerability affects FreeRDP from version 3.9.0 before 3.32.0. Limited source detail is available; defenders should verify client configurations and patch levels to prevent exposure.

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.