Vulnerability · Published Jul 10, 2026 · Assigned by GitHub_M
CVE-2026-55827FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode
High 7.5
In plain English
A high-severity out-of-bounds write in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% 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 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | freerdp | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| AlmaLinux:10 | freerdp-devel | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| AlmaLinux:10 | freerdp-libs | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| AlmaLinux:10 | freerdp-server | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| AlmaLinux:10 | libwinpr | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| AlmaLinux:10 | libwinpr-devel | 2:3.10.3-12.el10_2.7 | ALSA-2026:50747 |
| Alpine:v3.24 | freerdp | 3.27.1-r0 | ALPINE-CVE-2026-55827 |
| Debian:12 | freerdp2 | no fix listed | DEBIAN-CVE-2026-55827 |
| Debian:13 | freerdp3 | no fix listed | DEBIAN-CVE-2026-55827 |
| Debian:14 | freerdp3 | 3.27.1+dfsg-1 | DEBIAN-CVE-2026-55827 |
| Rocky Linux:10 | freerdp | 2:3.10.3-12.el10_2.7 | RLSA-2026:50747 |
| Ubuntu:22.04:LTS | freerdp2 | no fix listed | UBUNTU-CVE-2026-55827 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | UBUNTU-CVE-2026-55827 |
| 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-2026-55827 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | UBUNTU-CVE-2026-55827 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | USN-8561-1 |
Affected products (as reported)
Weakness: CWE-131, CWE-787 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp x_refsource_CONFIRM
- https://github.com/FreeRDP/FreeRDP/pull/12899 x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1 x_refsource_MISC