Buffer overflow in Freerdp
CVE-2026-121964
FreeRDP before 3.32.2 contains a heap-based buffer overflow in the RD Gateway RPC client, where rpc_client_recv_fragment writes BIND_ACK and ALTER_CONTEXT_RESP fragments into a persistent PDU stream after checking only total capacity rather than remaining capacity from the current stream position. A malicious or compromised RD Gateway can send crafted RPC fragments with manipulated alloc_hint and frag_length values to overwrite client heap memory with attacker-controlled data, causing a crash or potentially arbitrary code execution.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-q82v-5wjg-6h57 (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-buffer-overflow-via-rpc… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-121964?
- CVE-2026-121964 is a high-severity vulnerability in Freerdp, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-11-04.
- How severe is CVE-2026-121964?
- High severity. CVSS v3 base score is 7.5 out of 10.