Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.
Metrics
CVSS 3.1 9.8/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| FreeRDP | FreeRDP | < 3.21.0 |
| Red Hat | Red Hat Enterprise Linux 10 | — |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — |
| Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | — |
| Red Hat | Red Hat Enterprise Linux 8 | — |
| Red Hat | Red Hat Enterprise Linux 8.2 Advanced Update Support | — |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Telecommunications Update Service | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | — |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — |
| Red Hat | Red Hat Enterprise Linux 9 | — |
| Red Hat | Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | — |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — |
| Red Hat | Red Hat Enterprise Linux 9.4 Extended Update Support | — |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — |
| Red Hat | Red Hat Enterprise Linux 6 | — |
References
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L1139-L1145Product
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0Release Notes
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xj5h-9cr5-23c5Exploit, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:2048
- https://access.redhat.com/errata/RHSA-2026:2081
- https://access.redhat.com/errata/RHSA-2026:2222
- https://access.redhat.com/errata/RHSA-2026:2714
- https://access.redhat.com/errata/RHSA-2026:2736
- https://access.redhat.com/errata/RHSA-2026:2770
- https://access.redhat.com/errata/RHSA-2026:2824
- https://access.redhat.com/errata/RHSA-2026:2952
- https://access.redhat.com/errata/RHSA-2026:3036
- https://access.redhat.com/errata/RHSA-2026:3037
- https://access.redhat.com/errata/RHSA-2026:3038
- https://access.redhat.com/errata/RHSA-2026:3039
- https://access.redhat.com/errata/RHSA-2026:3041
- https://access.redhat.com/security/cve/CVE-2026-23531
- https://bugzilla.redhat.com/show_bug.cgi?id=2430887
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23531.json
Timeline
- Published
- Jan 19, 2026
- Last modified
- Jul 15, 2026
- NVD status
- Modified