CVE-2026-23948: FreeRDP has a NULL Pointer Dereference in rdp_write_logon_info_v2()

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-09 · updated 2026-06-17
Weakness: CWE-476

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, a NULL pointer dereference vulnerability in rdp_write_logon_info_v2() allows a malicious RDP server to crash FreeRDP proxy by sending a specially crafted LogonInfoV2 PDU with cbDomain=0 or cbUserName=0. This vulnerability is fixed in 3.22.0.

Affected products

FreeRDP: before 3.22.0 — fixed in 3.22.0

How to fix

Upgrade to a fixed version: FreeRDP 3.22.0. Check the vendor advisory for mitigations.

References

https://github.com/FreeRDP/FreeRDP/commit/4d44e3c097656a8b9ec696353647b0888ca45860
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6f3c-qvqq-2px5

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