FreeRDP before 3.32.2 Heap Out-of-Bounds Write in Planar Codec
Affects FreeRDP before 3.32.2 clients in a constrained address space, where a malicious server can trigger the planar codec bug. Fixed in 3.32.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- Proof of concept public, per CISA
- Fix
- Fixed in 3.32.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affects FreeRDP versions before 3.32.2 The client process runs in a constrained address space so the planar buffer allocation fails A malicious server sends an oversized ResetGraphics PDU followed by a GFX PLANAR command
- Exploitation15/40CISA rates a proof of concept as public
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity7.1/10CVSS 7.1
- No patch0/5No signal
What would change the score
- Would score about 69 if added to CISA KEV
- Would score about 64 if CISA's SSVC rates exploitation active
CVE-2026-121954 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.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 34/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 3.32.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
FreeRDP, an implementation of the Remote Desktop Protocol, has a heap out-of-bounds write in its planar codec that a malicious RDP server can trigger remotely, without logging in, by sending a crafted sequence of graphics commands. Exploitation can corrupt client heap memory and crash the client, and it requires the user to connect to the malicious server.
Read the original description
FreeRDP before 3.32.2 has a heap out-of-bounds write in the planar codec because freerdp_bitmap_planar_context_reset commits new dimensions before buffer reallocation succeeds, and a failed ResetGraphics is only logged. A malicious RDP server can send an oversized ResetGraphics PDU, then a GFX PLANAR command, to corrupt client heap memory and crash the client.
What to do
Check whether your setup matches what the bug needs.
Affects FreeRDP versions before 3.32.2 The client process runs in a constrained address space so the planar buffer allocation fails A malicious server sends an oversized ResetGraphics PDU followed by a GFX PLANAR commandUpgrade to a fixed version: 3.32.2.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- FreeRDP FreeRDP
fixed in 3.32.2
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121954
Is CVE-2026-121954 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. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A malicious server can send an oversized ResetGraphics PDU followed by a GFX PLANAR command. The client's planar buffer allocation can fail, and the client then writes past the end of a heap buffer and performs a NULL-pointer write, corrupting heap memory and crashing the client process.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-121954?
FreeRDP: before 3.32.2.Source: cve.now feed data
Am I affected, and how do I check?
FreeRDP versions before 3.32.2 are affected, and the planar buffer allocation failure requires the client process to run in a constrained address space. To check your installed version, run xfreerdp /version or check the version reported by your FreeRDP package manager.Source: vulncheck.com, github.com
How do I fix CVE-2026-121954?
Upgrade FreeRDP to version 3.32.2 or later, which contains the fix. The affected range ends before 3.32.2, so any earlier release should be replaced.Source: vulncheck.com, github.com