CVE-2026-22852Public exploitNetwork attack vector

Client memory corruption via stale AUDIN counter

Published Jan 14, 2026 · Updated Jan 14, 2026

Heap-buffer overflow in FreeRDP clients before 3.20.1 allows remote attackers to corrupt memory through crafted AUDIN format lists. The audin_process_formats function allocates a new formats array for each MSG_SNDIN_FORMATS PDU but retains formats_count, so a repeated list indexes past the new allocation. Exploitation requires a client connection to an attacker-controlled RDP server; the demonstrated consequence is a client crash.

CVSS severity9.8
Critical
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in FreeRDP clients before 3.20.1 allows remote attackers to corrupt memory through crafted AUDIN format lists. The audin_process_formats function allocates a new formats array for each MSG_SNDIN_FORMATS PDU but retains formats_count, so a repeated list indexes past the new allocation. Exploitation requires a client connection to an attacker-controlled RDP server; the demonstrated consequence is a client crash.

The record

CVE
CVE-2026-22852
Published
Jan 14, 2026
Updated
Jan 14, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 3.20.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=< 3.20.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8GitHub, Inc.CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
7.7SUSECVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.5SUSECVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

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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