Threat intelligence dashboard
CVE-2026-91948high

FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL

FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.

Risk score

7.7

CVSS 4.0

Vendor
FreeRDP
Product
FreeRDP
CWE
CWE-191
Published
Sep 15, 2026
Updated
Sep 16, 2026
CISA KEV
Not flagged

Affected products and versions

FreeRDP

FreeRDP

Version / rangeStatusType
3.28.0 to before 3.31.0affectedsemver
3.31.0unaffectedsemver

Technical metrics

7.7

CVSS 4.0

Severity
high
Source
VulnCheck
Vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

7.5

CVSS 3.1

Severity
high
Source
VulnCheck
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H