What’s Vulnerable › Vulnerabilities

CVE-2026-33977: FreeRDP: DoS via WINPR_ASSERT in IMA ADPCM audio decoder (dsp.c:331)

• Severity: medium (CVSS 6.5 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: 2026-03-30 · updated 2026-06-17
• Weakness: CWE-617

Description

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.

Affected products

• FreeRDP: before 3.24.2 — fixed in 3.24.2

How to fix

Upgrade to a fixed version: FreeRDP 3.24.2. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/commit/9be3f03d94a50892fd58a9f7dee72b2313c69b47
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8f2g-3q27-6xm5
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8f2g-3q27-6xm5

Get alerted when CVE-2026-33977 or the next vulnerability affects your stack