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CVE-2026-109939— FreeRDP 3.27.1 before 3.32.0 NULL Pointer Dereference via Cache Bitmap V3 Order

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 FreeRDP 3.27.1 至 3.32.0(不含 3.32.0)版本中,libfreerdp/core/orders.c 文件中的 update_read_cache_bitmap_v3_order() 函数存在空指针解引用漏洞。该漏洞会在 CBR3_DO_NOT_CACHE 标志被设置时,访问客户端位图缓存,而此时缓存尚未在“按需激活”(Demand Active)阶段完成初始化。如果恶意或已被攻陷的 RDP 服务器在连接建立阶段发送一个 Cache Bitmap V3 命令,可导致启用了非默认位图缓存

CVSS 6.5 · Medium

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 2

VendorProduct Version RangeStatus
FreeRDP FreeRDP 3.27.1< 3.32.0 affected
3.32.0 unaffected
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I. Basic Information for CVE-2026-109939

Vulnerability Information

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Vulnerability Title
FreeRDP 3.27.1 before 3.32.0 NULL Pointer Dereference via Cache Bitmap V3 Order
Source: CVE Program / CVE List V5
Vulnerability Description
FreeRDP 3.27.1 before 3.32.0 contains a NULL pointer dereference in update_read_cache_bitmap_v3_order() in libfreerdp/core/orders.c, which accesses the client bitmap cache when the CBR3_DO_NOT_CACHE flag is set, even though the cache is not yet initialized before Demand Active. A malicious or compromised RDP server can send a Cache Bitmap V3 order during connection setup to crash a connecting client that has enabled the non-default Bitmap Cache V3 feature (/cache:codec:<rfx|nsc|jpeg>).
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
空指针解引用
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
FreeRDP FreeRDP 3.27.1 ~ 3.32.0 -

II. Public POCs for CVE-2026-109939

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III. Intelligence Information for CVE-2026-109939

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Vendor Advisories for CVE-2026-109939 (2)

Same Patch Batch · FreeRDP · 2026-10-13 · 21 CVEs total

CVE-2026-109676 8.8 HIGH FreeRDP 3.0.0-beta1 before 3.32.0 Use-After-Free via Smartcard Connect
CVE-2026-109678 6.5 MEDIUM FreeRDP 3.0.0-beta1 before 3.32.0 Reachable Assertion via Emulated SCardStatusA
CVE-2026-109677 6.5 MEDIUM FreeRDP 2.0.0-beta1 before 3.28.0 Out-of-Bounds Read via LocateCardsByATRA Handler
CVE-2026-109942 6.5 MEDIUM FreeRDP 2.3.0 before 3.32.0 NULL Pointer Dereference via RD Gateway Close Channel Packet
CVE-2026-109941 6.5 MEDIUM FreeRDP 2.3.0 before 3.32.0 Infinite Loop via RD Gateway Chunked Response
CVE-2026-109938 6.5 MEDIUM FreeRDP 3.11.0 before 3.32.0 Integer Overflow via Mapped Video Geometry Update
CVE-2026-109946 6.5 MEDIUM FreeRDP 3.11.0 before 3.32.0 Reachable Assertion via AVC444 Odd Region Width
CVE-2026-109944 6.5 MEDIUM FreeRDP 3.0.0 before 3.32.0 Reachable Assertion via Stale Smartcard Handle
CVE-2026-109943 6.5 MEDIUM FreeRDP 3.29.0 before 3.32.0 Double Free via Async-Update Polygon Order
CVE-2026-109947 6.5 MEDIUM FreeRDP 3.20.1 before 3.32.0 Unbounded Allocation via drive_process_irp_read
CVE-2026-109949 6.5 MEDIUM FreeRDP 3.0.0 before 3.32.0 PIN Brute-Force via Virtual Smartcard
CVE-2026-109953 5.3 MEDIUM FreeRDP 3.0.0 before 3.32.0 Cleartext Credential Disclosure via /restricted-admin
CVE-2026-109952 5.3 MEDIUM FreeRDP 3.0.0 before 3.32.0 Security Protocol Downgrade via Negotiation Response
CVE-2026-109680 5.3 MEDIUM FreeRDP 3.18.0 before 3.32.0 Heap Out-of-Bounds Write via ARM Redirected Username
CVE-2026-109945 5.3 MEDIUM FreeRDP 3.0.0 before 3.32.0 Smartcard Use-After-Free via Concurrent Disconnect and Transmi
CVE-2026-109679 5.3 MEDIUM FreeRDP 3.0.0-beta4 before 3.32.0 NULL Pointer Crash via ARM Response
CVE-2026-109951 5.3 MEDIUM FreeRDP 3.17.1 before 3.32.0 Heap Buffer Over-Read via Proxy DRDYNVC Channel Name
CVE-2026-109940 4.3 MEDIUM FreeRDP 3.0.0-beta1 before 3.32.0 Stack Buffer Overflow via PKCS#11 Key Name
CVE-2026-109948 4.3 MEDIUM FreeRDP 3.0.0 before 3.32.0 Memory Disclosure via SCardTransmit Smartcard Redirection
CVE-2026-109950 4.3 MEDIUM FreeRDP 3.0.0 before 3.32.0 Heap Out-of-Bounds Read via RD Gateway Messages

IV. Related Vulnerabilities

V. Comments for CVE-2026-109939

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