# CVE-2026-121407: FreeRDP shadow server denial of service in remdesk channel

Source: https://junglewise.ai/threats/cve-2026-121407-freerdp-before-3-32-2-contains-a-denial-of-service-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-03. Updated: 2026-11-03  
License: CC BY 4.0 with a link back

CVE-2026-121407 · Severity: medium · CVSS 6.5 · Published 2026-11-03

FreeRDP's shadow server component enables remote desktop sharing and collaboration. An authenticated attacker can send a malformed network message over the remdesk channel that triggers a fatal assertion, crashing the server and disconnecting all active sessions. This impacts availability and causes denial of service.

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

## Quick answers

**Is CVE-2026-121407 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121407 being exploited in the wild.

**How severe is CVE-2026-121407?** Medium severity, with a CVSS score of 6.5, published 3 November 2026.

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

**Is there a fix for CVE-2026-121407?** 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-2026-121407 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-121407?** 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 exists in remdesk_server_thread where an inverted framing condition allows a malformed PDU with mismatched length declarations to overflow a 4096-byte stream buffer. An authenticated RDP client sends an 8192-byte payload claiming an 8-byte PDU length, causing Stream_Seek to trigger a fatal WinPR assertion when the stream position exceeds capacity. The attacker must authenticate to the RDP shadow server and join the remdesk static virtual channel.

## Affected products

- FreeRDP FreeRDP before 3.32.2

## Timeline

- 2026-10-19: disclosed
- 2026-11-03: advisory

## References

- [https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x8vp-ff7m-294g](https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x8vp-ff7m-294g)
- [https://www.vulncheck.com/advisories/freerdp-before-3.32.2-shadow-server-denial-of-service-via-remdesk-channel](https://www.vulncheck.com/advisories/freerdp-before-3.32.2-shadow-server-denial-of-service-via-remdesk-channel)

## Related threats

- [FreeRDP heap use-after-free in brush cache](https://junglewise.ai/threats/cve-2026-125394-freerdp-before-3-33-0-contains-a-heap-use-after-free)
- [FreeRDP heap buffer overflow in RD Gateway RPC client](https://junglewise.ai/threats/cve-2026-121964-freerdp-before-3-32-2-contains-a-heap-based-buffer-overflow-in)
- [FreeRDP use-after-free in dynamic rdpsnd channel](https://junglewise.ai/threats/cve-2026-121963-freerdp-before-3-32-2-contains-a-use-after-free-vulnerability-in)
- [FreeRDP denial of service in NLA shadow server via malformed TSRequest](https://junglewise.ai/threats/cve-2026-121960-freerdp-before-3-32-2-contains-a-denial-of-service-vulnerability)
- [FreeRDP heap out-of-bounds write in RDPGFX HashTable_GetKeys](https://junglewise.ai/threats/cve-2026-121958-freerdp-through-3-32-1-has-a-heap-out-of-bounds-write-in-the)