CVE-2026-64621Public exploit

Client crash via selectedmonitors double-free

Published Jul 20, 2026 · Updated Jul 20, 2026

Double free in FreeRDP before 3.28.0 allows context-dependent attackers to crash a CLI client via a crafted .rdp connection file. The selectedmonitors parser frees its settings-owned MonitorIds array on a strtoul overflow without clearing the owning pointer, so freerdp_settings_free() releases the same buffer again during teardown. Exploitation requires a victim to open the file; the demonstrated result is a client abort, while the published overlapping-allocation primitive does not demonstrate code execution.

CVSS severity9.3
Critical
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in FreeRDP before 3.28.0 allows context-dependent attackers to crash a CLI client via a crafted .rdp connection file. The selectedmonitors parser frees its settings-owned MonitorIds array on a strtoul overflow without clearing the owning pointer, so freerdp_settings_free() releases the same buffer again during teardown. Exploitation requires a victim to open the file; the demonstrated result is a client abort, while the published overlapping-allocation primitive does not demonstrate code execution.

The record

CVE
CVE-2026-64621
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-415, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.28.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=0 <3.28.0

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.3VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-415Double Free
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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