Vulnerability · Published May 29, 2026 · Assigned by GitHub_M
CVE-2026-44420FreeRDP cliprdr server heap-buffer-overflow via undersized capabilitySetLength in CB_CLIP_CAPS
High 8.8
In plain English
A high-severity heap buffer overflow in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 4.6% (higher than 92% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP client can trigger a heap-buffer-overflow write in FreeRDP's server-side clipboard (cliprdr) channel by sending a CB_CLIP_CAPS PDU with a too-small capabilitySetLength. This can crash the server process (remote DoS) and may be exploitable for code execution because it corrupts heap memory. This vulnerability is fixed in 3.26.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | freerdp | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| AlmaLinux:10 | freerdp-devel | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| AlmaLinux:10 | freerdp-libs | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| AlmaLinux:10 | freerdp-server | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| AlmaLinux:10 | libwinpr | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| AlmaLinux:10 | libwinpr-devel | 2:3.10.3-12.el10_2.6 | ALSA-2026:36203 |
| Debian:12 | freerdp2 | no fix listed | DEBIAN-CVE-2026-44420 |
| Debian:13 | freerdp3 | no fix listed | DEBIAN-CVE-2026-44420 |
| Debian:14 | freerdp3 | 3.26.0+dfsg-1 | DEBIAN-CVE-2026-44420 |
| Rocky Linux:10 | freerdp | 2:3.10.3-12.el10_2.6 | RLSA-2026:36203 |
| Ubuntu:22.04:LTS | freerdp2 | no fix listed | UBUNTU-CVE-2026-44420 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | UBUNTU-CVE-2026-44420 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | USN-8561-1 |
| Ubuntu:25.10 | freerdp3 | no fix listed | UBUNTU-CVE-2026-44420 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | UBUNTU-CVE-2026-44420 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | USN-8561-1 |
Affected products (as reported)
Weakness: CWE-122, CWE-131 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mvpx-xj7r-3p3r x_refsource_CONFIRM
- https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8 exploit
- https://access.redhat.com/security/cve/CVE-2026-44420 vdb-entry, x_refsource_REDHAT
- RHBZ#2483480 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44420.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:46393 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:36203 vendor-advisory, x_refsource_REDHAT