Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessControl malicious/compromised RD Gateway
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DeliveryVictim FreeRDP client connects through gateway
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ExploitSend consent/service message with oversized MsgBytes
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ExecutionTrigger heap out-of-bounds read during UTF-8 conversion
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ImpactCrash client (denial of service)
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK
1 technique across 1 tactic: Collection 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 attacker to control the RD Gateway (malicious or compromised) that a FreeRDP client (versions 3.0.0 up to but not including 3.32.0) connects through, and the victim client must actively initiate an RDP session via that gateway (UI:P). The specific trigger is a consent or service message in which the MsgBytes value is set far larger than the NDR string ActualCount, causing UTF-8 conversion to read past the stream allocation. Limiting factors: it is a client-side flaw (not exploitable against a server), it requires attacker control of the gateway plus the victim electing to connect through it, and the only outcome is a client-process crash (no code execution or data exposure). |
| Impact | This is a genuinely medium/low-priority issue rather than an urgent one, and the signals are internally consistent. The vendor-supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L) scores 5.3 and shows the only impact is a limited availability loss (VA:L) - a client crash - with no confidentiality or integrity impact and no scope change. Critically, exploitation requires an attacker to already control the RD Gateway the victim connects to, and requires passive user interaction (UI:P), i.e. the client voluntarily establishing an RDP session through the malicious gateway. This substantially narrows the realistic attacker population versus a server-side or fully unauthenticated-network flaw. No EPSS score, no POC, and no CISA KEV listing were provided in the input, and no public exploit is identified. The attack is a denial-of-service (client crash) only - there is no evidence of memory disclosure to the attacker or code execution despite the 'Information Disclosure' tag. Overall: a real but low-urgency availability bug; patch in normal cycles rather than as an emergency. |
| Exploit ScenarioDerived | An attacker who operates or has compromised an RD Gateway lures or coerces a FreeRDP-based client into connecting through it (UI:P). During the gateway handshake the attacker returns a consent or service message whose MsgBytes field is set far larger than the NDR string ActualCount, so the client's UTF-8 conversion reads past the end of the stream allocation and crashes. No public exploit code was identified at time of analysis; impact is limited to disrupting the victim client's availability. |
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Alert meAnalysisAIv1 – Oct 13, 2026
Malicious or compromised RD Gateway servers can crash FreeRDP clients running versions 3.0.0 up to but not including 3.32.0 by returning consent or service messages whose MsgBytes field is set far larger than the NDR string ActualCount, causing the UTF-8 conversion routine to read past the end of the stream allocation. The defect is a client-side heap out-of-bounds read (CWE-125) with a CVSS score of 5.3; the CVSS 4.0 vector indicates PR:N but UI:P, meaning the attacker needs no credentials on the client yet the victim must actively initiate an RDP session through the attacker-controlled gateway. The only confirmed outcome is a client-process crash - there is no code execution or data exposure - and at time of analysis there is no public exploit identified and the issue is not in CISA KEV; a vendor fix is available in FreeRDP 3.32.0.
RemediationAI
Upgrade to FreeRDP 3.32.0 or later, which is the version boundary stated in the vendor advisory (GHSA-xf45-j844-588v); this is the only complete fix because the flaw is in the client's message-parsing code. Until the upgrade can be deployed, the most effective compensating control is to stop trusting arbitrary gateways: remove untrusted or third-party RD Gateways from client configuration, restrict connections to a vetted gateway list via policy (for example hardening /gateway settings or deployment configuration), and avoid RDP-over-gateway sessions to destinations the user does not control - the trade-off is loss of legitimate remote access through those gateways. Where gateway use is unavoidable, run the FreeRDP client under a restricted user account and, on Linux or BSD, under a sandbox (firejail, bubblewrap, or an equivalent) so a successful crash cannot escalate, and enable client-level crash reporting and restart supervision so a crash of the RDP session does not take down a wider desktop session or automation job. Because this is an availability-only bug on the client side, network controls such as blocking outbound TCP 443 to unknown destinations or forcing direct RDP (TCP 3389/VPN) instead of gateway-mediated RDP remove the attack path entirely, at the cost of that connectivity pattern. Note that the affected message parsing is not authentication-dependent, so no credential policy change mitigates it; every factual fix version here comes from the vendor advisory and the referenced VulnCheck write-up.
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 a cross-platform open-source implementation of the Remote Desktop Protocol; the vulnerable code lives in its client-side RD Gateway (RDP over HTTPS / TS Gateway) handling, which parses consent and service messages exchanged with the gateway before the RDP session is established. Those messages carry NDR-encoded strings, where the ActualCount field declares the real string length and the surrounding MsgBytes field describes the byte length of the message body. When a malicious gateway sets MsgBytes to a value far larger than ActualCount, the subsequent UTF-8 conversion step trusts the inflated length and reads beyond the heap allocation that holds the received stream. This is the classic CWE-125 out-of-bounds read pattern: a length/value mismatch between two protocol fields that a peer controls, with no re-validation before the conversion loop. The affected component is the FreeRDP library itself (CPE cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*, version-agnostic, so the affected range must be taken from the advisory: 3.0.0 through 3.31.x). The CVE is reported by VulnCheck and tagged as a buffer overflow / information disclosure issue, but the authoritative assessment is that the observable impact is availability only (VC:N/VI:N/VA:L) - the over-read corrupts control flow at most into a crash and is not demonstrated to leak heap contents back to the attacker.
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Network-reachable malicious gateway (AV:N/AC:L/PR:N), but the victim client must connect through it (UI:R), and impact is limited to a client crash (A:L, C:N/I:N).
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
2DescriptionCVE.org
FreeRDP from 3.0.0 before 3.32.0 contains a heap out-of-bounds read vulnerability that allows a malicious RD Gateway to crash clients by sending mismatched message lengths. Attackers controlling the gateway can set MsgBytes far larger than the NDR string ActualCount in consent or service messages, causing UTF-8 conversion to read past the stream allocation and disrupt client availability.
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 buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Use-after-free in FreeRDP xf_clipboard_format_equal before 3.23.0. Clipboard format comparison uses freed memory. Fifth
Use-after-free in FreeRDP xf_AppUpdateWindowFromSurface before 3.23.0. Surface-to-window update triggers memory corrupti
Use-after-free in FreeRDP xf_SetWindowMinMaxInfo before version 3.23.0. X11 client window management triggers memory cor
Use-after-free in FreeRDP xf_cliprdr_provide_data clipboard handling before 3.23.0. Clipboard data exchange triggers mem
FreeRDP IRP thread handler has a use-after-free where the IRP is freed by Complete() then accessed on the error path. Fi
FreeRDP drive read heap overflow when server-controlled read length exceeds IRP output buffer. Fixed in 3.20.1. PoC avai
FreeRDP client before 3.20.1 has a heap buffer overflow in AUDIN format processing. A malicious RDP server can corrupt m
Use-after-free in FreeRDP xf_AppUpdateWindowFromSurface before 3.23.0. Different code path from CVE-2026-25953. PoC and
FreeRDP is a free implementation of the Remote Desktop Protocol. Rated critical severity (CVSS 9.8), this vulnerability
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Rated critical
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Rated critical
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Rated critical
EUVD-2026-98654
GHSA-6j8x-gjmp-55pr
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB