FreeRDP: Heap buffer overflow in server-side rdpsnd audio channel
Summary
FreeRDP before 3.32.1 contains a heap-based buffer overflow in the server-side rdpsnd audio redirection channel. An integer wraparound in rdpsnd_server_select_format() bypasses validation, so a malicious RDP client that sends two crafted SNDC_FORMATS messages can cause an unbounded heap write during server audio playback. The vendor advisory describes this as a bypass of an earlier fix (CVE-2026-63117), and code execution is possible.
Affected
- FreeRDP before 3.32.1 (CNA range 0 to below 3.32.1)
- FreeRDP stable 3.32.0
- FreeRDP master up to commit 8ec6d3923b8951e11cda8cbd2983494aeb60ce90 (2026-09-23)
- Distribution packages: unknown, check your distro security tracker
Fixed in
- FreeRDP 3.32.1 (vendor release notes list this advisory)
- Distribution patch status: unknown, verify that the package contains the fix
Workaround
- Disable audio redirection (rdpsnd) on RDP servers that do not need it
- Restrict RDP access to VPN or management networks until patched
No other mitigation is confirmed by the vendor.
Exploitation
- Public proof-of-concept code is included in the vendor advisory; not independently reproduced here
- CISA SSVC: exploitation none, automatable no, technical impact total
- Not listed in CISA KEV
- In-the-wild exploitation: unknown
Our recommendation
- Inventory all FreeRDP instances, including server builds, embedded devices and packaged copies, and record their versions
- Upgrade to FreeRDP 3.32.1 or later, or install a distribution patch once it is confirmed to contain the fix
- Prioritise internet-exposed RDP servers with audio redirection
- Until patched, disable audio redirection where not needed and restrict RDP access
- Check whether RDP sessions require authentication (for example Network Level Authentication) and monitor RDP servers for unusual connections
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-3m9q-g533-rqjq github.com
- VulnCheck advisory: FreeRDP before 3.32.1 heap buffer overflow www.vulncheck.com
- FreeRDP 3.32.1 release notes www.freerdp.com
- OSV record CVE-2026-114045 osv.dev
- Ubuntu security tracker CVE-2026-114045 ubuntu.com
- VulDB entry 423877 vuldb.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 01:13.
Original description (NVD)
FreeRDP before 3.32.1 contains a heap-based buffer overflow in the server-side rdpsnd channel because an integer wraparound in rdpsnd_server_select_format() DVI_ADPCM block-alignment arithmetic bypasses validation. A malicious RDP client can send two SNDC_FORMATS PDUs with an nBlockAlign too small for nChannels, causing an unbounded heap write during server audio playback, potentially enabling code execution.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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