CVEvulnerability

CVE-2026-22858

5.6 MEDIUM Published 2026-01-14 Modified 2026-07-15 Official page ↗
Status
Modified
Published
2026-01-14
Last modified
2026-07-15
Assigner
[email protected]
CVSS 4.0 ([email protected])
5.6 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
7.4 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Weaknesses
CWE-125, CWE-758, CWE-787

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.

Affected configurations

• freerdp freerdp (< 3.20.1)

Related

Weakness · CWE (3)

  • CWE-125 Out-of-bounds Read weakness
  • CWE-758 Reliance on Undefined, Unspecified, or Implementation-Defined Behavior weakness
  • CWE-787 Out-of-bounds Write weakness

References