VULNERABILITY INTELLIGENCE

CVE-2026-22858

CVSS score9.1 CRITICAL
EPSS probability0.70%
CISA KEVNot currently listed
Published2026-01-14
Last modified2026-07-15
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

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.

Weakness classification

  • security-advisories@github.com: CWE-125
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-787

Primary references