CVE-2026-31883Public exploitNetwork attack vector

Client memory corruption via ADPCM size underflow

Published Mar 13, 2026 · Updated Mar 13, 2026

Heap-buffer-overflow write in FreeRDP before 3.24.0 allows remote attackers to corrupt client memory via crafted RDPSND audio. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract header lengths from size_t counters without first checking that enough input remains. A malicious RDP server must negotiate RDPSND during an active client session; automatic audio decoding can crash the client and corrupt adjacent heap objects.

CVSS severity6.5
Medium
EPSS probability0.32%
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 write in FreeRDP before 3.24.0 allows remote attackers to corrupt client memory via crafted RDPSND audio. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract header lengths from size_t counters without first checking that enough input remains. A malicious RDP server must negotiate RDPSND during an active client session; automatic audio decoding can crash the client and corrupt adjacent heap objects.

The record

CVE
CVE-2026-31883
Published
Mar 13, 2026
Updated
Mar 13, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-191, CWE-122, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 13, 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=< 3.24.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=< 3.24.0

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
9.8NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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-191Integer Underflow (Wrap or Wraparound)
CWE-122Heap-based Buffer Overflow
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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