CVE-2026-121962— FreeRDP before 3.32.2 Heap Buffer Overflow via Early User Authorization Read

Quick assessment

Affected

FreeRDP FreeRDP

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 3.32.2 版本之前的 FreeRDP 中，当在 PROTOCOL_HYBRID_EX CredSSP 协议下处理部分 Early User Authorization（EUA）读取时，函数存在堆缓冲区溢出漏洞。恶意的 RDP 服务器可将四字节的 EUA 结果拆分为多次短读取，导致流指针超出 16 KiB 的预分配范围，从而引发越界写入，造成客户端拒绝服务（DoS）。

CVSS 8.1 · High Updated Nov 05, 2026

Possible ATT&CK Techniques 2 AI

T1203 · Exploitation for Client Execution T1190 · Exploit Public-Facing Application

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Vulnerability Information

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Vulnerability Title

FreeRDP before 3.32.2 Heap Buffer Overflow via Early User Authorization Read

Source: CVE Program / CVE List V5

Vulnerability Description

FreeRDP before 3.32.2 contains a heap buffer overflow in transport_default_read_pdu when handling partial Early User Authorization reads during PROTOCOL_HYBRID_EX CredSSP. A malicious RDP server can split the four-byte EUA result into short reads that advance the stream pointer beyond the 16 KiB allocation, causing an out-of-bounds write and client denial of service.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

跨界内存写

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
FreeRDP	FreeRDP	0 ~ 3.32.2	-

II. Public POCs for CVE-2026-121962

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-121962

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Other References for CVE-2026-121962 (2)

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-j536-qc58-pmf8 vendor-advisory
https://www.vulncheck.com/advisories/freerdp-before-3.32.2-heap-buffer-overflow-via-early-user-authorization-read third-party-advisory

https://www.cve.org/CVERecord?id=CVE-2026-121962

Same Patch Batch · FreeRDP · 2026-11-04 · 15 CVEs total

CVE-2026-121952	9.8 CRITICAL	FreeRDP before 3.32.2 Proxy Out-of-Bounds Write via Bitmap Cache v2 Capability
CVE-2026-121953	9.8 CRITICAL	FreeRDP before 3.32.2 Use-After-Free via rdpgfx Dynamic Virtual Channel Close
CVE-2026-121958	8.8 HIGH	FreeRDP through 3.32.1 Heap Out-of-Bounds Write via RDPGFX HashTable_GetKeys
CVE-2026-121951	7.5 HIGH	FreeRDP 3.0.0 before 3.32.2 Denial of Service via Slow-Path Input Event
CVE-2026-121955	7.5 HIGH	FreeRDP before 3.32.2 Use-After-Free in Smartcard Emulation ReleaseContext
CVE-2026-121956	7.5 HIGH	FreeRDP before 3.32.2 Double Free in WinPR Kerberos retrieveSomeTgt
CVE-2026-121957	7.5 HIGH	FreeRDP before 3.32.2 Use-After-Free via RDPGFX ResetGraphics Race
CVE-2026-121960	7.5 HIGH	FreeRDP before 3.32.2 Unauthenticated Denial of Service via CredSSP TSRequest
CVE-2026-121964	7.5 HIGH	FreeRDP before 3.32.2 Heap Buffer Overflow via rpc_client_recv_fragment
CVE-2026-121950	6.5 MEDIUM	FreeRDP before 3.32.2 Heap Overflow via RDPGFX CREATE_SURFACE Integer Wrap
CVE-2026-121954	6.5 MEDIUM	FreeRDP before 3.32.2 Heap Out-of-Bounds Write in Planar Codec
CVE-2026-121959	6.5 MEDIUM	FreeRDP before 3.32.2 Infinite Loop via Truncated WebSocket Frame
CVE-2026-121961	5.9 MEDIUM	FreeRDP before 3.32.2 Use-After-Free via DRDYNVC Tracker Race
CVE-2026-121963	5.9 MEDIUM	FreeRDP before 3.32.2 Use-After-Free via Dynamic rdpsnd Channel Close

IV. Related Vulnerabilities

Same product: FreeRDP

Same vendor: FreeRDP

Same weakness: CWE-787