Pre-authentication input injection in FreeRDP shadow server
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-306.
Summary
FreeRDP shadow server from 3.0.0 before 3.32.0 dispatches input PDUs during the Confirm Active state before authentication, a missing authentication flaw (CWE-306). An unauthenticated remote attacker can negotiate TLS-only RDP and inject synthetic keystrokes into the host user's X11 session. The references include an exploit link.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
Description from the CNA
FreeRDP shadow server from 3.0.0 before 3.32.0 dispatches input PDUs during the Confirm Active state before authentication, allowing unauthenticated attackers to inject keyboard input. Attackers can negotiate TLS-only RDP and send an input PDU without Confirm Active to inject synthetic keystrokes into the host user's X11 session via XTEST.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
FreeRDP 3.32.0 fixes the flaw. Red Hat fixes it in RHSA-2026:94514 for Red Hat Enterprise Linux AppStream (v. 10) and CodeReady Linux Builder (v. 10).
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
- Fix · CNA FreeRDP (FreeRDP) Fixed in 3.32.0
Red Hat 1 advisory
- RHSA-2026:94514 Released 2026-11-03 · Red Hat rating Importantfreerdp 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 3.32.0
11 records Highest priority Priority HIGH 1 HIGH, 9 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-74520 FreeRDP serial device handling exhausts file descriptorsPriority HIGH 69
- TI-2026-74529 Heap out-of-bounds write in FreeRDP JPEG clipboard conversionPriority MEDIUM 64
- TI-2026-74526 FreeRDP Infinite Loop DoS via Gateway Content-TypePriority MEDIUM 64
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:94514 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:94514 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-15 Threatist record created from CVE-2026-110838
- 2026-10-16 Priority changed: MEDIUM → LOW
- 2026-10-16 Affected versions changed · Red Hat
- 2026-10-16 CVSS score added · Red Hat
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-16 Priority changed: LOW → MEDIUM
- 2026-11-03 Fix available: RHSA-2026:94514 · Red Hat
- 2026-11-03 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat
References
More Freerdp vulnerabilities
- 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
Sources
- CVE-2026-110838 · CVE Program
- CVE-2026-110838 · NVD
- FIRST EPSS
- CVE-2026-110838 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences