CVE-2026-31884

Description

A division by zero flaw has been discovered in FreeRDP. This division by zero exists in the MS-ADPCM and IMA-ADPCM decoders when nBlockAlign is 0, leading to a crash. In libfreerdp/codec/dsp.c, both ADPCM decoders use size % block_size where block_size = context->common.format.nBlockAlign. The nBlockAlign value comes from the Server Audio Formats PDU on the RDPSND channel. The value 0 is not validated anywhere before reaching the decoder. When nBlockAlign = 0, the modulo operation causes a SIGFPE (floating point exception) crash.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.57.56.5
Attack VectorNetworkNetworkNetwork
Attack ComplexityLowLowLow
Privileges RequiredNoneNoneNone
User InteractionRequiredNoneRequired
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneNoneNone
Integrity ImpactNoneNoneNone
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Understanding the Weakness (CWE)

CWE-369

Availability

Technical Impact: DoS: Crash, Exit, or Restart

A Divide by Zero results in a crash.

Frequently Asked Questions

Not sure what something means? Check out our Security Glossary.

Want to get errata notifications? Sign up here.