Buffer overflow in Freerdp
CVE-2026-55193
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients using TS Gateway accept a server-controlled max_xmit_frag value in libfreerdp/core/gateway/rpc_bind.c without bounding it to the 4088-byte ReceiveFragment allocation. A malicious gateway can advertise 65535 and then send a response fragment of the same length, causing rpc_channel_read in libfreerdp/core/gateway/rpc.c to write up to 65535 bytes into the smaller ReceiveFragment buffer. This can crash the client and may permit code execution through attacker-controlled heap corruption. This issue is fixed in version 3.27.0.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (36.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.000
Affected products
- Freerdp — versions < 3.27.0
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rp4-66mc-j9vx (Exploit, Vendor Advisory)
- github.com/FreeRDP/FreeRDP/pull/12873 (Patch, Issue Tracking)
- github.com/FreeRDP/FreeRDP/commit/a863ef1cf1cdabf9019280e5658f806e73bb50e8 (Patch)
- github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-55193?
- CVE-2026-55193 is a high-severity vulnerability in Freerdp, classified under Heap-based Buffer Overflow. CVSS score: 8.8/10. Published 2026-08-19.
- How severe is CVE-2026-55193?
- High severity. CVSS v3 base score is 8.8 out of 10.