CVE-2026-33977 — Reachable Assertion in Freerdp

CWE-617 — Reachable AssertionCWE-1285 — Improper Validation of Specified Index, Position, or Offset in Input6 documents6 sources
Severity
6.9MEDIUMNVD
EPSS
0.0%
top 88.48%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
1
Freerdp
Timeline
PublishedMar 30

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 …

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected Packages2 packages

▶CVEListV5freerdp/freerdp< 3.24.2
▶NVDfreerdp/freerdp< 3.24.2

Patches

Patch: github.com ↗Patch: github.com ↗Patch: github.com ↗

🔴Vulnerability Details

2
CVEList
FreeRDP: DoS via WINPR_ASSERT in IMA ADPCM audio decoder (dsp.c:331)↗2026-03-30
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OSV
CVE-2026-33977: FreeRDP is a free implementation of the Remote Desktop Protocol↗2026-03-30
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📋Vendor Advisories

2
Red Hat
FreeRDP: FreeRDP: Denial of Service via malformed IMA ADPCM audio data↗2026-03-30
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Debian
CVE-2026-33977: freerdp2 - FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to versio...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-33977 Impact, Exploitability, and Mitigation Steps | Wiz↗
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