What is CVE-2026-121399?

CVE-2026-121399 is a medium-severity vulnerability in Freerdp, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2026-11-03.

How severe is CVE-2026-121399?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Resource exhaustion in Freerdp

CVE-2026-121399

FreeRDP before 3.32.2 contains a memory allocation vulnerability in rdg_receive_packet that allows a malicious RD Gateway to force a 2 GiB client allocation before tunnel authentication. Attackers can send an eight-byte RDG header declaring packet length 0x7FFFFFFF to trigger pre-authentication memory exhaustion and denial of service.

Published 2026-11-03 · last modified 2026-11-03.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Freerdp

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4vh4-3pc3-32p7 (vendor-advisory, Vendor Advisory)
www.vulncheck.com/advisories/freerdp-before-3.32.2-memory-exhaustion-via-rd-gat… (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-121399?: CVE-2026-121399 is a medium-severity vulnerability in Freerdp, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2026-11-03.
How severe is CVE-2026-121399?: Medium severity. CVSS v3 base score is 4.3 out of 10.