Vulnerability in Freerdp
CVE-2026-33977
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (30.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Freerdp — versions < 3.24.2
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8f2g-3q27-6xm5 (Exploit, Patch, Mitigation, Vendor Advisory)
- github.com/FreeRDP/FreeRDP/commit/9be3f03d94a50892fd58a9f7dee72b2313c69b47 (Patch)
Frequently asked questions
- What is CVE-2026-33977?
- CVE-2026-33977 is a medium-severity vulnerability in Freerdp, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-03-30.
- How severe is CVE-2026-33977?
- Medium severity. CVSS v3 base score is 6.5 out of 10.