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FreerdpApplication

CVE-2026-22853

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-14
Fix available
A fix is available. Upgrade to 3.20.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, RDPEAR’s NDR array reader does not perform bounds checking on the on‑wire element count and can write past the heap buffer allocated from hints, causing a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in 3.20.1.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

FreeRDP contains a heap buffer overflow vulnerability in the RDPEAR NDR array reader. The ndr_read_uint8Array function fails to validate the element count received from the network before allocating and writing data to the heap buffer, allowing an attacker to write past allocated boundaries by sending specially crafted RDP messages with oversized element counts.

MitigationUpgrade FreeRDP to version 3.20.1 or later. For systems where upgrading is not immediately feasible, restrict RDP access to trusted networks or implement network-level filtering to limit exposure to untrusted RDP connections.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreerdpApplication
Affected:< 3.20.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check FreeRDP client version
    Run 'freerdp-version' or 'xfreerdp /version' to obtain the installed FreeRDP version. On Linux, also check package manager output (dpkg -l freerdp or rpm -qa freerdp).
    Affected if The version is lower than 3.20.1 (e.g., 3.19.x, 3.18.x, 2.x series, or any version string that does not start with 3.20.1 or higher).
  2. Identify FreeRDP client usage
    Check for running FreeRDP client processes (xfreerdp, wfreerdp, or the freerdp executable) or active RDP sessions originating from FreeRDP clients using process monitoring tools (ps, tasklist, or similar).
    Affected if FreeRDP client is actively used to connect to RDP servers, as the vulnerability is triggered during the server-to-client NDR data processing.
  3. Confirm RDPEAR protocol usage
    Inspect network captures or RDP session logs for RDPEAR (Remote Desktop Protocol Extension for Access Rights) traffic, which occurs during authentication and session initialization. This is typically present in most RDP connections.
    Affected if RDP sessions are established with servers that send RDPEAR data, as the ndr_read_uint8Array function processes this data.
  4. Assess server trust boundary
    Evaluate whether FreeRDP clients connect only to trusted/internal RDP servers or may connect to untrusted/external servers. Check RDP connection configurations, saved connection profiles, or connection history.
    Affected if FreeRDP clients connect to untrusted or externally-accessible RDP servers, as the vulnerability is exploited by a malicious server sending specially crafted NDR array data.

The environment is affected if FreeRDP version is below 3.20.1 AND FreeRDP clients are used to connect to RDP servers (particularly untrusted ones), since the heap overflow occurs when processing RDPEAR NDR array data sent by the server.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.20.1 or later
Fixed in 3.20.1
Interim mitigation

Upgrade FreeRDP to version 3.20.1 or later. For systems where upgrading is not immediately feasible, restrict RDP access to trusted networks or implement network-level filtering to limit exposure to untrusted RDP connections.

Recommended fix High confidence

FreeRDP 3.20.1

  1. Obtain FreeRDP version 3.20.1 or later from the official FreeRDP repository or your distribution's package manager
  2. Verify the current installed version of FreeRDP to confirm it is below 3.20.1
  3. Upgrade FreeRDP to version 3.20.1 or newer using your system's package management tools
  4. Restart any FreeRDP-related services or applications if applicable
  5. Verify the installed version is now 3.20.1 or later
Caveat Review release notes for 3.20.1 to check for any API or feature changes that may affect existing integrations

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Freerdp Scoped from the published advisory
  • Consultation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $880
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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-22853 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data