Reachable assertion in FreeRDP - CVE-2026-33977
Published: April 8, 2026
Vulnerability identifier: #VU125372
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33977
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to reachable assertion in freerdp_dsp_decode_ima_adpcm() and dsp_decode_ima_adpcm_sample() in libfreerdp/codec/dsp.c when processing RDPSND IMA ADPCM audio data from a server. A remote attacker can send a specially crafted audio block with an invalid initial step index to cause a denial of service.
Audio redirection must be enabled, which is the default configuration.
Affected software
FreeRDP
Fedora
freerdp
Fedora
freerdp
How to mitigate CVE-2026-33977
Install security update from vendor's website.
FreeRDP - update to 3.24.2
freerdp - addressed in versions 3.24.2-1.fc42, 3.24.2-1.fc43, 3.24.2-1.fc44
freerdp - addressed in versions 3.24.2-1.fc42, 3.24.2-1.fc43, 3.24.2-1.fc44