Medium severity · published Aug 19, 2026
CVE-2026-63652
FreeRDP: Double-free of `client_formats` in the rdpsnd server channel on a malformed Client Audio Formats PDU
6.5
CVSS
0.6%
EPSS
No
On KEV
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, rdpsnd_server_recv_formats in channels/rdpsnd/server/rdpsnd_main.c frees context->client_formats on a malformed Client Audio Formats PDU without clearing the owning pointer or num_client_formats. An authenticated RDP client can trigger an error such as a cbSize larger than the remaining record, leave the dangling pointer in the server context, and cause rdpsnd_server_context_free to free the same allocation again at session teardown. This reliably terminates the server and can create allocator-dependent heap corruption. This issue is fixed in version 3.28.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRDP · FreeRDP
< 3.28.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63652
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63652
Patch
https://github.com/FreeRDP/FreeRDP/commit/caf653c0ba1c75ec8f298d1baa59770102a5d14c
Issue Tracking
https://github.com/FreeRDP/FreeRDP/pull/12993
Release Notes
https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0
Exploit
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9g22-w2gr-vcmp
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