FreeRDP Audio Crash via Invalid IMA ADPCM Step Index < 3.24.2
CVE-2026-33977 Published on March 30, 2026
FreeRDP: DoS via WINPR_ASSERT in IMA ADPCM audio decoder (dsp.c:331)
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, a malicious RDP server can crash the FreeRDP client by sending audio data in IMA ADPCM format with an invalid initial step index value (>= 89). The unvalidated step index is read directly from the network and used to index into a 89-entry lookup table, triggering a WINPR_ASSERT() failure and process abort via SIGABRT. This affects any FreeRDP client that has audio redirection (RDPSND) enabled, which is the default configuration. This issue has been patched in version 3.24.2.
Weakness Type
What is an assertion failure Vulnerability?
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
CVE-2026-33977 has been classified to as an assertion failure vulnerability or weakness.
Products Associated with CVE-2026-33977
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Affected Versions
FreeRDP Version < 3.24.2 is affected by CVE-2026-33977Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.