# CVE-2026-121964: FreeRDP heap buffer overflow in RD Gateway RPC client

Source: https://junglewise.ai/threats/cve-2026-121964-freerdp-before-3-32-2-contains-a-heap-based-buffer-overflow-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-121964 · Severity: high · CVSS 7.5 · Published 2026-11-04

FreeRDP is a remote desktop client used to connect to Windows systems. A malicious or compromised RD Gateway can send crafted RPC messages that cause the client to write data beyond allocated memory boundaries, leading to a client crash or potentially allowing arbitrary code execution with the privileges of the user running the client.

Technologies: [FreeRDP](https://junglewise.ai/threats/technologies/freerdp). Vendors: [FreeRDP](https://junglewise.ai/threats/vendors/freerdp).

## Quick answers

**Is CVE-2026-121964 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121964 being exploited in the wild.

**How severe is CVE-2026-121964?** High severity, with a CVSS score of 7.5, published 4 November 2026.

**Which products and versions are affected?** FreeRDP before 3.32.2.

**Is there a fix for CVE-2026-121964?** Yes: fixed in 3.32.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-121964 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-121964?** Check whether you run FreeRDP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 3.32.2

## Technical details

The vulnerability is a heap-based buffer overflow in the rpc_client_recv_fragment function where BIND_ACK and ALTER_CONTEXT_RESP fragments are written to a persistent PDU stream. The function checks only total buffer capacity rather than remaining capacity from the current stream position, allowing a malicious RD Gateway to send crafted fragments with manipulated alloc_hint and frag_length values to overwrite heap memory. The vulnerability requires network access to an RD Gateway endpoint but no authentication or user interaction beyond initiating a connection.

## Affected products

- FreeRDP FreeRDP before 3.32.2

## Timeline

- 2026-10-20: disclosed
- 2026-11-04: advisory

## References

- [https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-q82v-5wjg-6h57](https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-q82v-5wjg-6h57)
- [https://www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-buffer-overflow-via-rpc-client-recv-fragment](https://www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-buffer-overflow-via-rpc-client-recv-fragment)

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