# CVE-2026-121954: FreeRDP heap out-of-bounds write in planar codec

Source: https://junglewise.ai/threats/cve-2026-121954-freerdp-before-3-32-2-has-a-heap-out-of-bounds-write-in-the  
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-2026-121954 · Severity: medium · CVSS 6.5 · Published 2026-11-04

FreeRDP is a remote desktop client used to connect to Windows systems over RDP. A malicious RDP server can send specially crafted graphics commands to crash the FreeRDP client or corrupt its memory, potentially allowing the attacker to execute code on the client machine.

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

## Quick answers

**Is CVE-2026-121954 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121954 being exploited in the wild.

**How severe is CVE-2026-121954?** Medium severity, with a CVSS score of 6.5, published 4 November 2026.

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

**Is there a fix for CVE-2026-121954?** 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-2026-121954 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-121954?** 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 planar codec in FreeRDP's freerdp_bitmap_planar_context_reset function commits new buffer dimensions before successfully allocating the required memory. When a ResetGraphics PDU with oversized dimensions fails allocation, the geometry state remains updated while buffers retain their old, smaller sizes. A subsequent GFX PLANAR command then writes beyond these buffers' bounds, causing heap corruption. Attack requires an RDP handshake and active connection state but no user interaction.

## 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-fg78-v8j5-8697](https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-fg78-v8j5-8697)
- [https://www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-out-of-bounds-write-in-planar-codec](https://www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-out-of-bounds-write-in-planar-codec)

## 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)