FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's planar bitmap decoder has an out-of-bounds heap write when decoding RLE planar data. In libfreerdp/codec/planar.c, freerdp_bitmap_decompress_planar() validates the X destination coordinate nXDst against the caller-provided destination stride (nDstStep) even when it is writing into the internal temp buffer pTempData. An attacker can bypass the check with a large nDstStep and a large nXDst, causing planar_decompress_plane_rle() to write past the end of pTempData. This vulnerability is fixed in 3.26.0.
| Version | Base score | Base severity | Vector |
|---|---|---|---|
| 4.0 | 7.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CAPEC ID | Description |
|---|
| Event | Date |
|---|
| Hyperlink | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mpxh-8fq3-x8mh | x_refsource_CONFIRM |
| Version | Base score | Base severity | Vector |
|---|
| CAPEC ID | Description |
|---|
| Event | Date |
|---|
| Hyperlink | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mpxh-8fq3-x8mh | exploit |
A flaw was found in FreeRDP, a free implementation of the Remote Desktop Protocol. The planar bitmap decoder contains an out-of-bounds heap write vulnerability when processing RLE planar data. A remote attacker could exploit this by providing specially crafted RLE planar data, leading to an out-of-bounds write. This could result in arbitrary code execution or a denial of service.
| Version | Base score | Base severity | Vector |
|---|---|---|---|
| 3.1 | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| CAPEC ID | Description |
|---|
RHSA-2026:47201: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS)
RHSA-2026:46393: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
RHSA-2026:36203: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
RHSA-2026:38501: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8)
RHSA-2026:46384: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
RHSA-2026:46389: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)
RHSA-2026:46388: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8)
RHSA-2026:47048: Red Hat Enterprise Linux AppStream E4S (v.9.2)
RHSA-2026:46383: Red Hat Enterprise Linux AppStream E4S (v.9.4)
RHSA-2026:47049: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6)
RHSA-2026:37207: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
To reduce exposure, restrict FreeRDP connections to trusted remote desktop servers. Avoid connecting to untrusted RDP endpoints, as processing malicious RLE planar data from such a server could trigger the vulnerability.
| Event | Date |
|---|---|
| Reported to Red Hat. | 2026-05-29 21:01:21 |
| Made public. | 2026-05-29 19:44:12 |