CVE-2026-91956Public exploitNetwork attack vectorHinoki check available

Client crash via mismatched URBDRC interface indexing

Published Sep 15, 2026 · Updated Sep 15, 2026

Out-of-bounds read in FreeRDP before 3.31.0 allows remote attackers controlling an RDP server to crash clients through URBDRC. The func_get_ep_desc function indexes LibusbConfig interface arrays by position while validation uses the protocol InterfaceNumber, then uses the server-controlled AlternateSetting without a matching bounds check. USB redirection must be enabled and the client must connect to a malicious or compromised RDP server; the uncontrolled pointer dereference crashes the client but does not provide code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Out-of-bounds read in FreeRDP before 3.31.0 allows remote attackers controlling an RDP server to crash clients through URBDRC. The func_get_ep_desc function indexes LibusbConfig interface arrays by position while validation uses the protocol InterfaceNumber, then uses the server-controlled AlternateSetting without a matching bounds check. USB redirection must be enabled and the client must connect to a malicious or compromised RDP server; the uncontrolled pointer dereference crashes the client but does not provide code execution.

The record

CVE
CVE-2026-91956
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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 <3.31.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=0 <3.31.0

Published CVSS scores

No CVSS assessment is available in this record.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

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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