CVE-2026-64620
Heap overflow in FreeRDP allows unauthenticated pre-auth DoS via crafted RSA ciphertext.
Is CVE-2026-64620 being exploited?
Not confirmed. CVE-2026-64620 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.85% probability of exploitation in the next 30 days.
How severe is CVE-2026-64620?
CVE-2026-64620 is rated Critical. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-64620?
Yes. A fix has been recorded for CVE-2026-64620. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64620 affect?
CVE-2026-64620 affects FreeRDP <= 3.27.1, RDP servers using FreeRDP, Products embedding FreeRDP. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64620?
Upgrade FreeRDP to 3.28.0+; restrict/disable RDP Standard Security until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can trigger a pre-auth heap buffer overflow when RDP Standard Security is used, causing denial of service and potential memory corruption.
Immediate action required
- affected< 3.28.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.