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.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 3.32.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected FreeRDP versions are before 3.32.2. The attack requires a malicious or compromised RD Gateway. The gateway must complete the tunnel-open exchange, so the tunnel reaches the opened state before the packet is sent.
- Exploitation0/40No signal
- Exposure15/25Specific setups only, CISA rates it automatable
- 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 72 if added to CISA KEV
- Would score about 67 if CISA's SSVC rates exploitation active
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.
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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? →
- 22/100 · 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: none
- Automatable: yes
- Technical impact: partial
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.
Read the original 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 whether your setup matches what the bug needs.
Affected FreeRDP versions are before 3.32.2. The attack requires a malicious or compromised RD Gateway. The gateway must complete the tunnel-open exchange, so the tunnel reaches the opened state before the packet is sent.Upgrade to a fixed version: 3.32.2.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · 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-2026-121400
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: cve.now feed data
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: vulncheck.com, github.com
Which versions are affected by CVE-2026-121400?
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 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: vulncheck.com, github.com
How do I fix CVE-2026-121400?
Upgrade FreeRDP to 3.32.2 or later. The facts list no workaround.Source: vulncheck.com, github.com