Quick answers
- Is CVE-2026-55194 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-55194 being exploited in the wild.
- How severe is CVE-2026-55194?
- Critical severity, with a CVSS score of 9.8, published 19 August 2026.
- Which products and versions are affected?
- FreeRDP prior to 3.27.0.
- Is there a fix for CVE-2026-55194?
- A patch was published on 2026-06-11: Fix merged in PR #12873 and released in version 3.27.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-55194 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-55194?
- Check whether you run FreeRDP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a heap buffer overflow in the rpc_client_recv_fragment function within libfreerdp/core/gateway/rpc_client.c. The root cause is that the code allocates buffer capacity based on the server-declared alloc_hint value rather than validating against the actual StubLength that will be written. A malicious TS Gateway can send a PTYPE_RESPONSE packet with a small alloc_hint but a much larger frag_length, causing Stream_Write to overflow the 4096-byte pdu->s buffer. The attack requires a network-reachable TS Gateway or a man-in-the-middle position; no user interaction or prior authentication is strictly required to trigger the overflow. Successful exploitation can lead to process crash (denial of service) or heap corruption enabling remote code execution. The vulnerability is fixed in version 3.27.0.
Affected products
- FreeRDP FreeRDP prior to 3.27.0
Timeline
- 2026-08-19: disclosed
- 2026-06-11: patched: Fix merged in PR #12873 and released in version 3.27.0