Read the docs

FreeRDP shadow server lets clients exhaust CPU with empty messages

Priority LOW 31CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 2 fixed, 4 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-400.

Summary

FreeRDP before 3.32.2 has a denial of service flaw in its shadow server. The server does not consume zero-length drdynvc DATA messages sent on opened audin or rdpgfx channels, so its threads spin with CWE-400 uncontrolled resource consumption. An authenticated remote RDP client with low privileges can consume full CPU cores until it disconnects.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

FreeRDP before 3.32.2 contains a denial of service vulnerability in the shadow server that allows authenticated RDP clients to spin server threads by sending zero-length drdynvc DATA PDUs. Attackers can send empty DATA messages on opened audin or rdpgfx channels, so that FreeRDP_WTSVirtualChannelRead never consumes them, consuming full CPU cores until disconnect.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00383 32nd percentileScored 2026-11-07
Fix Partial FreeRDP (FreeRDP): 3.32.2Red Hat: 1 advisoryRed Hat: 2 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeRDPFreeRDPbefore 3.32.23.32.2Patch availableCNA
  • FreeRDP VendorFreeRDP Affected before 3.32.2 Fixed in 3.32.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*before 3.32.2VulnerableFreeRDP
  • cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* Versions before 3.32.2 Vulnerable ·FreeRDP

Remediation

Update FreeRDP to version 3.32.2. Red Hat fixes this in Red Hat Enterprise Linux AppStream (version 10) and CodeReady Linux Builder (version 10) with advisory RHSA-2026:94514. Red Hat has no fix planned for Red Hat Enterprise Linux 6, 7, 8 and 9.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA FreeRDP (FreeRDP) Fixed in 3.32.2

Red Hat 1 advisory

  • RHSA-2026:94514 Released 2026-11-03 · Red Hat rating Important
    freerdp security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) freerdp-2:3.32.2-1.el10_2, freerdp-libs-2:3.32.2-1.el10_2, libwinpr-2:3.32.2-1.el10_2
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-devel-2:3.32.2-1.el10_2, freerdp-server-2:3.32.2-1.el10_2, libwinpr-devel-2:3.32.2-1.el10_2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    FreeRDP 3.32.2

    27 records Highest priority Priority HIGH 3 HIGH, 11 MEDIUM, 13 LOW

    Other records, highest priority first

    • TI-2026-84268 Denial of service in FreeRDP WinPR PNG and JPEG image readersPriority HIGH 77
    • TI-2026-84291 Denial of service in FreeRDP via oversized X.224 routing tokenPriority HIGH 69
    • TI-2026-84280 Use-after-free in FreeRDP dyn-channel-dump modulePriority HIGH 69

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:94514
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:94514

Timeline

  1. 2026-11-03 Threatist record created from CVE-2026-121404
  2. 2026-11-03 Alias added: GHSA-26v7-mr7m-fqqx
  3. 2026-11-03 CISA SSVC decision points changed
  4. 2026-11-03 Priority changed: MEDIUM → LOW
  5. 2026-11-04 Affected versions changed · Red Hat
  6. 2026-11-04 CVSS score added · Red Hat
  7. 2026-11-04 Fix available: RHSA-2026:94514 · Red Hat
  8. 2026-11-04 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat

References

  • TI-2026-85092 Use-after-free in FreeRDP rdpgfx channel close handling CVSS 4.0CRITICAL 9.3
  • TI-2026-85091 Out-of-bounds write in FreeRDP proxy via bitmap cache v2 capability CVSS 4.0CRITICAL 9.3
  • TI-2026-24435 FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write CVSS 3.1CRITICAL 9.8
  • TI-2023-21373 Out-Of-Bounds Write in FreeRDP CVSS 3.1CRITICAL 9.8
  • TI-2022-08692 Server side NTLM does not properly check parameters in FreeRDP CVSS 3.1CRITICAL 9.1
  • TI-2023-21374 Out-Of-Bounds Read in FreeRDP CVSS 3.1CRITICAL 9.1
See all 336 →

Sources