FreeRDP flaws get public exploits, with three rated critical

FreeRDP flaws get public exploits, with three rated critical

5 November 2026: FreeRDP, the open source Remote Desktop Protocol implementation, has a large batch of newly patched flaws with public proof-of-concept code: Italy's ACN counts three as critical and 24 as high, and the worst two, CVE-2026-121953 and CVE-2026-121952, score CVSS 9.8. ACN reports no attacks so far. FreeRDP's own advisories give 3.32.2 as the fix for most of them, and 3.33.0 shipped on 2 November.

Not yet independently verified. FreeRDP's advisories mostly show no CVE number, so linking the three CVEs named here to a specific fixed version rests on matching ACN's descriptions with advisory titles. ACN reports public proof-of-concept code, not attacks. We will update this when it can be confirmed, and remove this note.

A malicious server for one bug, a malicious client for the other

The two 9.8 flaws point in opposite directions, and that decides who is exposed.

CVE-2026-121953 is a use-after-free in dynamic virtual channel handling. When a server opens duplicate channels with the same name and different ChannelId values, the callback reference is overwritten and memory is freed without the pointer being cleared. So a crafted RDP server can crash the connecting client or, under some conditions, run code as the user of that client.

CVE-2026-121952 is an out-of-bounds write in the Proxy component, caused by inadequate checks on numCellCaches in Bitmap Cache V2. Here a crafted RDP client attacks the proxy, with memory corruption, denial of service, memory disclosure or in special cases code execution as the result.

CVE-2026-121392, at CVSS 7.4, weakens the protection against interception. The TLS check accepts a certificate's Common Name even when the Subject Alternative Names do not match, and it validates an IP target against DNS-type SANs. A machine-in-the-middle holding a suitable certificate could then pass as the intended server.

Which versions carry the fixes

• FreeRDP 3.32.2: the fixed version in most advisories published on 19 and 20 October, which cover versions up to 3.32.1.
• FreeRDP 3.33.0: released on 2 November, described by the project as the usual bug and CVE fixes, and the newest release.
• 3.22.2 branch: a few advisories list a fix here instead, so anyone on the older line should read each advisory rather than assume.

FreeRDP often arrives inside something else

Few organisations install FreeRDP on purpose. It reaches them inside Linux desktop clients such as Remmina and KRDC, inside browser-based remote access gateways such as Apache Guacamole, and inside distribution packages that backport fixes without changing the version number. Check the package changelog as well as the version string.

Two groups have the most to do. Staff who connect out to servers they do not control carry the client-side risk, which also makes the channel flaw a concern on helpdesk and consultancy laptops. Anyone running the FreeRDP proxy where untrusted clients can reach it carries the other.

We list 20 remote desktop products, and a vendor whose product builds on FreeRDP should be able to say which release it bundles.

Sources

• ACN (Italy's national cybersecurity agency): FreeRDP, PoC available for multiple vulnerabilities, 5 November 2026, 5 November 2026
• FreeRDP security advisories on GitHub, published 19 and 20 October 2026 (read 6 November 2026), 6 November 2026
• FreeRDP releases: 3.33.0, 2 November 2026, 2 November 2026