CVE-2026-67297 FreeRDP CVE debrief

Who should care

Defenders responsible for FreeRDP deployments should assess exposure and prioritize patching to prevent potential resource exhaustion attacks. This includes verifying FreeRDP versions and applying patches, monitoring for potential malicious RD Gateway endpoints, and implementing additional security measures to prevent resource exhaustion attacks. Defenders should also review compensating controls for exposed systems while remediation is scheduled and

Why it matters

Defenders should care about CVE-2026-67297 because it allows attackers to exhaust client memory resources via chunked HTTP responses, potentially leading to denial of service (DoS) attacks. FreeRDP deployments should assess exposure and prioritize patching to prevent potential resource exhaustion attacks. The vulnerability requires verification of FreeRDP versions and patch application to prevent exploitation.

• Potential resource exhaustion attacks via chunked HTTP responses
• Possible denial of service (DoS) due to memory exhaustion
• Need for verification of FreeRDP versions and patch application

Technical summary

FreeRDP before 3.29.0 fails to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can send oversized chunked response bodies to exhaust client memory resources without triggering the configured size limit. This vulnerability allows attackers to exhaust client memory resources via chunked HTTP responses, potentially leading to denial of service (DoS) attacks. Defenders should prioritize verifying FreeRDP versions and applying patches to prevent potential resource exhaustion attacks.

Defensive priority

Defenders should prioritize verifying FreeRDP versions and applying patches to prevent potential resource exhaustion attacks.

Recommended defensive actions

• Verify FreeRDP versions and apply patches to prevent potential resource exhaustion attacks
• Monitor for potential malicious RD Gateway endpoints
• Implement additional security measures to prevent resource exhaustion attacks
• 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 and NVD vulnerability detail page provide information on the vulnerability, including its description, CVSS score, and affected versions. The vulnerability is caused by FreeRDP's failure to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can send oversized chunked response bodies to exhaust client memory resources without triggering the configured size limit. Verification of FreeRDP versions and

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.