CVE-2026-31885: FreeRDP has an out-of-bounds read in ADPCM decoders due to missing predictor/step_index bounds checks

Severity: critical (CVSS 9.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-13 · updated 2026-06-17
Weakness: CWE-125

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, there is an out-of-bounds read in MS-ADPCM and IMA-ADPCM decoders due to unchecked predictor and step_index values from input data. This vulnerability is fixed in 3.24.0.

Affected products

FreeRDP: before 3.24.0 — fixed in 3.24.0

How to fix

Upgrade to a fixed version: FreeRDP 3.24.0. Check the vendor advisory for mitigations.

References

https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h23r-3988-3wf3
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h23r-3988-3wf3

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