CVE-2026-91953

Medium

Description

FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.

SeverityMedium

CVSS6.5

Exploit probability—

ProductFreerdp

PublishedSep 15, 2026

First seenSep 15, 2026

Weakness typeCWE-120CWE-120

How to fix

Update

freerdp freerdp3.31.0 or later

Vendor advisories

github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6

Affected products

Product	Affected versions	Fixed in
freerdp freerdp	v < 3.31.0	3.31.0

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.