VulnerabilityModified

CVE-2026-22858

FreeRDP is a free implementation of the Remote Desktop Protocol.

MEDIUM 5.6EPSS 0.69%

Does this matter?

Lower severity and a low EPSS score (0.69%). Track it; it rarely justifies an emergency change on its own.

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 4.0: 5.6 MEDIUMCVSS: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/M
EPSS: 0.69% probability · 51th percentile
CISA KEV: Not listed
Weakness: CWE-125, CWE-758, CWE-787
Affected: freerdp/freerdp
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.