Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0 can be optimized into a simple c != 0 check. As a result, non-ASCII bytes (e.g., 0x80-0xFF) may bypass the intended range restriction and be used as an index into a global lookup table, causing out-of-bounds access. This vulnerability is fixed in 3.20.1.
Metrics
CVSS 3.1 9.1/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| FreeRDP | FreeRDP | < 3.20.1 |
| 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/releases/tag/3.20.1Release Notes
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896Exploit, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:19033
- https://access.redhat.com/errata/RHSA-2026:3067
- https://access.redhat.com/errata/RHSA-2026:3068
- https://access.redhat.com/errata/RHSA-2026:3334
- https://access.redhat.com/errata/RHSA-2026:3975
- https://access.redhat.com/errata/RHSA-2026:4121
- https://access.redhat.com/errata/RHSA-2026:4433
- https://access.redhat.com/errata/RHSA-2026:4437
- https://access.redhat.com/errata/RHSA-2026:4438
- https://access.redhat.com/errata/RHSA-2026:4439
- https://access.redhat.com/errata/RHSA-2026:4440
- https://access.redhat.com/errata/RHSA-2026:4446
- https://access.redhat.com/errata/RHSA-2026:4471
- https://access.redhat.com/errata/RHSA-2026:4489
- https://access.redhat.com/security/cve/CVE-2026-22858
- https://bugzilla.redhat.com/show_bug.cgi?id=2429649
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22858.json
Timeline
- Published
- Jan 14, 2026
- Last modified
- Jul 15, 2026
- NVD status
- Modified