CVE-2026-23948Network attack vector

Proxy crash via zero-length LogonInfoV2 fields

Published Feb 9, 2026 · Updated Feb 9, 2026

NULL pointer dereference in FreeRDP before 3.22.0 allows remote attackers controlling an RDP server to crash the FreeRDP proxy. The rdp_write_logon_info_v2() path passes a NULL domain or username to strnlen() after accepting a LogonInfoV2 PDU whose cbDomain or cbUserName field is zero. Exploitation requires the proxy to connect to a malicious RDP server; the resulting process crash interrupts every client using that proxy instance.

CVSS severity6.9
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in FreeRDP before 3.22.0 allows remote attackers controlling an RDP server to crash the FreeRDP proxy. The rdp_write_logon_info_v2() path passes a NULL domain or username to strnlen() after accepting a LogonInfoV2 PDU whose cbDomain or cbUserName field is zero. Exploitation requires the proxy to connect to a malicious RDP server; the resulting process crash interrupts every client using that proxy instance.

The record

CVE
CVE-2026-23948
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 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=< 3.22.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=< 3.22.0

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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