High severity · published Sep 15, 2026
CVE-2026-91964
FreeRDP 2.0.0 through 3.30.0 Heap Buffer Overflow via RoutingToken
8.8
CVSS
0.6%
EPSS
No
On KEV
Description
FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in nego_send_negotiation_request when processing Server Redirection PDU messages with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can trigger the overflow by sending an arbitrary-length field that gets written to a fixed 512-byte buffer without validation, causing client crashes or potential code execution when chained with memory disclosure.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRDP · FreeRDP
2.0.0 before 3.0.0; 3.0.0 before 3.31.0; before 3.31.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91964
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91964
github.com
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2vf2-grvj-6g8x
www.vulncheck.com
https://www.vulncheck.com/advisories/freerdp-2.0.0-through-3.30.0-heap-buffer-overflow-via-routingtoken
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