HOMEVULNERABILITIESCVE-2026-33977
MEDIUM

CVE-2026-33977

CWE-617Published: March 30, 2026· Updated: Apr 1, 2026

6.5
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:12.9th

Official 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.

NVD Source

Technical Analysis

CVE-2026-33977 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected Vendors & Products

FreeRDP1 product
freerdp
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

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

All References (3)

→
https://github.com/FreeRDP/FreeRDP/commit/9be3f03d94a50892fd58a9f7dee72b2313c69b47Patch
→
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8f2g-3q27-6xm5Exploit · Mitigation · Patch · Vendor Advisory
→
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8f2g-3q27-6xm5Exploit · Mitigation · Patch · Vendor Advisory

Quick Facts

CVE IDCVE-2026-33977
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-617
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 30, 2026

Related CVEs (CWE-617)

CVE-2026-29116
8.7
CVE-2026-41485
7.7
CVE-2026-37221
7.5
CVE-2026-37222
7.5
CVE-2026-27135
7.5
CVE-2026-34063
7.5

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-33977 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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