CVE-2026-64621: FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp

Routine

HIGH 7.3UPGRADE

CVE-2026-64621 is a high-severity flaw (CVSS 7.3) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated through the settings object, and a raw non-owning pointer to it is freed on the strtoul error path without clearing settings->MonitorIds, leaving it dangling; at teardown freerdp_settings_fr

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.3 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-415
Published	2026-07-20
Last modified	2026-07-28

Publisher (CNA): VulnCheck · Vendor: freerdp

Last updated 2026-07-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-20 12:19 UTCPublished CVE record published
2026-07-28 15:34 UTCUpdated Record last modified

freerdp freerdp UPGRADE

Affected: >= 3.0.0 and < 3.28.0

Fixed in: 3.28.0

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy freerdp || rpm -q freerdp || freerdp --version

2. UPGRADE to 3.28.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade freerdp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freerdp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison freerdp sudo apt install freerdp=<VERSION_BEFORE_3.0.0> sudo apt-mark hold freerdp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list freerdp sudo dnf downgrade freerdp-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add freerdp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-64621?

freerdp: upgrade to 3.28.0. Exact commands for each OS are on this page.

Is CVE-2026-64621 being exploited?

CVE-2026-64621 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-64621 affect?

CVE-2026-64621 affects freerdp. Severity is high (CVSS 7.3). FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds

How urgent is CVE-2026-64621?

Priority 38/100. High severity; Public exploit reference

Software pages

WinRM and RDP vulnerabilities

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References

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