What is CVE-2026-121959?

CVE-2026-121959 is a medium-severity vulnerability in Freerdp, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 6.5/10. Published 2026-11-04.

How severe is CVE-2026-121959?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Freerdp

CVE-2026-121959

FreeRDP before 3.32.2 contains an infinite loop vulnerability in websocket_context_read that fails to handle a zero BIO result with payload outstanding. A malicious RD Gateway can send a truncated WebSocket frame followed by a TLS close_notify, causing a client thread to spin and consume CPU until killed.

Published 2026-11-04 · last modified 2026-11-05.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

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-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x26g-fp9v-c2pg (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
www.vulncheck.com/advisories/freerdp-before-3.32.2-infinite-loop-via-truncated-… (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-121959?: CVE-2026-121959 is a medium-severity vulnerability in Freerdp, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 6.5/10. Published 2026-11-04.
How severe is CVE-2026-121959?: Medium severity. CVSS v3 base score is 6.5 out of 10.