Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessLure victim to connect FreeRDP client
-
DeliveryNegotiate rdpsnd audio channel
-
ExploitSend malformed fragment (LAST without FIRST)
-
ExecutionDereference null pointer in handler
-
ImpactCrash client (denial of service)
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires the victim to run a FreeRDP client (versions 3.0.0 through 3.31.x) and initiate an RDP session to an attacker-controlled or compromised server, with the rdpsnd (audio redirection) channel negotiated - the malformed PDU must arrive on a fresh channel. The specific trigger is a rdpsnd fragment with CHANNEL_FLAG_LAST set but CHANNEL_FLAG_FIRST absent. Limiting factors: the attacker must occupy the server side of the connection (not an arbitrary remote host), the user must actively connect (UI:P / passive interaction), and the outcome is only a client crash - there is no confidentiality, integrity, or code-execution impact. Clients that never connect to untrusted servers, or deployments on FreeRDP 3.32.0+, are not exposed. |
| Impact | This is a client-side denial-of-service vulnerability with impact strictly limited to availability - the CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H) confirms no confidentiality or integrity impact, only VA:H, consistent with the CWE-476 null pointer dereference and the 'crash the client' description. The 7.1 score reflects the availability-only impact plus the required passive user interaction (UI:P): the attack is network-reachable and needs no authentication (PR:N), but it is a malicious-server-attacks-client model, so a victim must be induced to connect their FreeRDP client to an attacker-controlled or compromised RDP server. No EPSS score, CISA KEV listing, or public POC was provided in the intelligence, so there is no evidence of active exploitation or weaponization - exploitation status is 'no public exploit identified at time of analysis.' The realistic priority is MODERATE-to-LOW: a crash-only bug cannot be used for code execution or data theft, and the server-side-attacker requirement limits mass exploitation; it matters most where FreeRDP clients auto-connect to untrusted gateways/brokers. Note a signal nuance: PR:N technically means unauthenticated, but the practical attacker position is 'operator of the RDP server the victim connects to,' which is a meaningful limiting factor the raw score does not convey. |
| Exploit ScenarioDerived | An attacker stands up or compromises an RDP server and lures a user to connect their FreeRDP-based client (e.g., via a malicious gateway, phishing link, or man-in-the-middle). Once the rdpsnd audio channel is negotiated on a fresh connection, the server sends a malformed rdpsnd PDU fragment with CHANNEL_FLAG_LAST set but not CHANNEL_FLAG_FIRST, triggering a null pointer dereference that crashes the client. No public exploit code was identified in the provided intelligence; impact is limited to a denial of service with no code execution. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Oct 14, 2026
Null pointer dereference in the FreeRDP client's rdpsnd (audio redirection) channel allows a malicious or compromised RDP server to crash any connecting client running FreeRDP 3.0.0 through 3.31.x, producing a denial of service that terminates the user's RDP session. The trigger is a malformed rdpsnd fragment that sets CHANNEL_FLAG_LAST without CHANNEL_FLAG_FIRST and arrives on a fresh channel; the CVSS vectors (4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VA:H, and the assessed 3.1 equivalent AV:N/AC:L/PR:N/UI:R/A:H) confirm unauthenticated remote reach but strictly availability-only impact - no confidentiality, integrity, or code-execution effect. Exploitation requires the victim to initiate a session against the attacker's server and to have audio redirection negotiated; there is no evidence of in-the-wild exploitation and no public exploit identified at time of analysis.
RemediationAI
Upgrade the FreeRDP client to 3.32.0 or later, which is the first release containing the fix for the rdpsnd fragment-parsing flaw (vendor advisory: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mq5-xh88-9v62); since this is a client-side bug, patching only the server component does not remove the risk - every host that initiates outbound RDP sessions needs the updated client, and organizations that embed libfreerdp should rebuild against 3.32.0. Where an immediate upgrade is not possible, disable audio redirection so the rdpsnd channel is never negotiated: use the client's audio switch such as '/sound:off' (or '-sound off'), adding it to launcher shortcuts, RDP file templates, and managed client configurations so users cannot silently re-enable it; the trade-off is loss of remote audio for legitimate users, and any application that requests audio redirection explicitly may still negotiate the channel unless the policy is enforced. A second, complementary control is to restrict client-initiated RDP connections to a known set of trusted servers via host-based firewall or egress policy, which blocks the attacker-controlled-server precondition entirely but breaks legitimate remote-work and admin workflows to non-allowlisted hosts. Note that KEV monitoring and POC repositories contain no entry for this issue and no public exploit code has been identified, so the practical priority is routine client patching rather than emergency response.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
FreeRDP is an open-source implementation of the Remote Desktop Protocol; the rdpsnd channel is the virtual channel that carries audio redirection between server and client. Virtual channel data is delivered in fragments governed by control flags: CHANNEL_FLAG_FIRST marks the beginning of a logical PDU and CHANNEL_FLAG_LAST marks its end. The client-side reassembly logic assumes the first fragment (the one bearing CHANNEL_FLAG_FIRST) initializes the state used by subsequent fragments; when a server sends a fragment with CHANNEL_FLAG_LAST set but CHANNEL_FLAG_FIRST absent on a fresh channel, that state pointer is never populated and is dereferenced anyway. This is a classic CWE-476 null pointer dereference, which on most platforms manifests as a hard crash (SIGSEGV / access violation) rather than a controllable memory-corruption primitive, which is why the impact is confined to availability. The vulnerable window spans the FreeRDP 3.x line from 3.0.0 up to, but not including, 3.32.0; the upstream GitHub security advisory GHSA-3mq5-xh88-9v62 and the VulnCheck advisory FREERDP-3.0.0-BEFORE-3.32.0 document the issue.
Know when the next one hits your stack
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Network-reachable malicious server, low complexity, no auth (PR:N), but victim must connect so UI:R; impact is availability-only crash, hence C:N/I:N/A:H.
Primary rating from Vendor (vulncheck).
CVSS VectorVendor: vulncheck
Lifecycle Timeline
2DescriptionCVE.org
FreeRDP versions from 3.0.0 before 3.32.0 contain a null pointer dereference in the rdpsnd channel when a fragment sets CHANNEL_FLAG_LAST without CHANNEL_FLAG_FIRST. A malicious RDP server can send a malformed rdpsnd PDU on a fresh channel to crash the client and cause denial of service.
Technical POC Analysis
CWE-476 null pointer dereference in FreeRDP's client-side rdpsnd (static audio redirection) channel.
Full technical POC analysis - root cause, step-by-step exploitation and patch breakdown - is part of the Pro and Business plans.
Executive ViewAI
FreeRDP client versions 3.0.0 through 3.31.x are affected by a null pointer dereference in the rdpsnd audio redirection channel, enabling a malicious RDP server to crash the client and terminate the user's session. This unauthenticated remote denial-of-service affects remote workers and support staff who connect to external RDP servers, potentially disrupting business operations, but it does not compromise data confidentiality or integrity. Since no vendor patch is currently available and no public exploit has been identified, leadership should prioritize interim mitigations to maintain availability for critical remote access functions.
Disable audio redirection (rdpsnd) in FreeRDP clients, restrict RDP connections to trusted servers, and monitor for client crashes. No vendor-released patch identified at time of analysis.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
EUVD-2026-101712
GHSA-45cr-5r62-8qcj
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB