CVE-2026-22858
Modified
Modified - Updated After Analysis
BaseFortify
Vulnerability report for CVE-2026-22858, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-01-14
Last updated on: 2026-06-30
Assigner: GitHub, Inc.
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| freerdp | freerdp | to 3.20.1 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-758 | The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity. |
| CWE-125 | The product reads data past the end, or before the beginning, of the intended buffer. |
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
