FreeRDP has a global-buffer-overflow in crypto_base64_decode_CVE-2026-22858

5.6 / 10

MEDIUM

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P

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.

Basic Information

ID CVE-2026-22858

Source GitHub_M

Published Jan 14, 2026 at 17:56

Affected Product

Vendor FreeRDP

Product FreeRDP

Version < 3.20.1

Affected Versions FreeRDP FreeRDP < 3.20.1

CWE Classification

CWE-125 CWE-758

References

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    "published": "2026-01-14T17:56:29.729Z",
    "modified": "2026-01-14T17:56:29.729Z",
    "type": "cve",
    "title": "FreeRDP has a global-buffer-overflow in crypto_base64_decode",
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    "references": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896\nhttps://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1",
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