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FreerdpApplication

CVE-2026-23884

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-19
Fix available
A fix is available. Upgrade to 3.21.0 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 version 3.21.0, offscreen bitmap deletion leaves `gdi->drawing` pointing to freed memory, causing UAF when related update packets arrive. A malicious server can trigger a client‑side use after free, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

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

In FreeRDP clients prior to version 3.21.0, the offscreen bitmap deletion routine fails to nullify the `gdi->drawing` pointer after freeing the associated memory. This leaves a dangling pointer that gets dereferenced when subsequent RDP update packets are processed, triggering a use-after-free condition. A malicious RDP server can send specially crafted update packets to cause heap corruption and potential code execution on the client.

MitigationUpgrade FreeRDP to version 3.21.0 or later. Until patched, restrict RDP connections to trusted servers only, as an compromised server can exploit this vulnerability.

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:< 3.21.0

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 installed FreeRDP version
    Run 'freerdp-version' or 'xfreerdp --version' from the command line, or check the package manager for the freerdp package version (e.g., dpkg -l freerdp, rpm -qi freerdp)
    Affected if The reported version is lower than 3.21.0 (e.g., 3.20.0, 3.19.x, 2.x, etc.)
  2. Verify FreeRDP library version
    If using FreeRDP as a library, check the shared library version (e.g., ldconfig -p | grep freerdp, or check libfreerdp*.so* files in /usr/lib/)
    Affected if The library version is below 3.21.0
  3. Confirm client usage scenario
    Determine if the system runs FreeRDP-based RDP client software to connect to remote servers. This includes command-line clients (xfreerdp, x11freerdp) or applications using FreeRDP libraries
    Affected if FreeRDP client software is installed and used to connect to RDP servers
  4. GDI rendering is active by default
    The GDI component is used automatically during standard RDP sessions for graphics rendering. No specific configuration check is needed for this component to be present
    Affected if Standard RDP sessions are conducted - the vulnerability triggers when offscreen bitmaps are deleted during normal graphics operations

A user is affected if they run any FreeRDP version prior to 3.21.0 as an RDP client to connect to servers, since the Use-After-Free in GDI triggers during normal graphics rendering operations.

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 3.21.0 or later
Fixed in 3.21.0
Interim mitigation

Upgrade FreeRDP to version 3.21.0 or later. Until patched, restrict RDP connections to trusted servers only, as an compromised server can exploit this vulnerability.

Recommended fix High confidence

FreeRDP 3.21.0

  1. 1. Identify the current FreeRDP version installed on the system using package manager or freerdp-version command
  2. 2. For package-based systems: update package repository metadata and upgrade freerdp package to version 3.21.0 or later
  3. 3. For source builds: download FreeRDP 3.21.0 or later from the official repository (github.com/FreeRDP/FreeRDP)
  4. 4. Rebuild and reinstall the new version following standard build procedures (cmake, make, make install)
  5. 5. Verify the installed version is 3.21.0 or higher using freerdp-version or equivalent
  6. 6. Restart any FreeRDP client sessions to ensure the patched version is loaded

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

Fix this in Freerdp Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2026-23884 in production — separate from our analysis above.

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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