What’s Vulnerable › Vulnerabilities

CVE-2026-55193: FreeRDP: Heap-buffer-overflow write in TS Gateway RPC fragment receive due to uncapped bind_ack max_xmit_frag

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-19 · updated 2026-10-26
• Weakness: CWE-122

Description

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.

Affected products

• FreeRDP: before 3.27.0 — fixed in 3.27.0

How to fix

Upgrade to a fixed version: FreeRDP 3.27.0. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/commit/a863ef1cf1cdabf9019280e5658f806e73bb50e8
• https://github.com/FreeRDP/FreeRDP/pull/12873
• https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rp4-66mc-j9vx

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