CVE-2026-26271Network attack vector

Client crash via undersized icon mask

Published Feb 25, 2026 · Updated Feb 25, 2026

Buffer over-read in FreeRDP before 3.23.0 allows remote attackers to crash an RDP client with crafted Window Icon data. freerdp_image_copy_from_icon_data derives an alpha-mask stride from the icon dimensions but reads the mask without confirming that cbBitsMask covers the indexed rows. Exploitation requires a malicious RDP server or man-in-the-middle to supply the icon during a client session, and the published impact is limited to interrupting that client process.

CVSS severity5.3
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer over-read in FreeRDP before 3.23.0 allows remote attackers to crash an RDP client with crafted Window Icon data. freerdp_image_copy_from_icon_data derives an alpha-mask stride from the icon dimensions but reads the mask without confirming that cbBitsMask covers the indexed rows. Exploitation requires a malicious RDP server or man-in-the-middle to supply the icon during a client session, and the published impact is limited to interrupting that client process.

The record

CVE
CVE-2026-26271
Published
Feb 25, 2026
Updated
Feb 25, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-126, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 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=< 3.23.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=< 3.23.0

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.5GitHub, 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/E:P

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-126Buffer Over-read
T1203Exploitation for Client Execution

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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