Uncapped memory allocation in FreeRDP lets RDP servers exhaust memory
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- 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-770.
Summary
FreeRDP from 3.0.0 before 3.32.2 has an uncontrolled resource allocation flaw (CWE-770) in its dynamic channel handling. A malicious RDP server can declare DRDYNVC DATA_FIRST lengths up to 4,294,967,295 bytes on running dynamic channels, so StreamPool_Take reserves memory before the body is validated. A user connecting to such a server can have client memory exhausted.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
FreeRDP from 3.0.0 before 3.32.2 contains an uncontrolled resource allocation vulnerability that allows malicious RDP servers to force large client allocations through the DRDYNVC DATA_FIRST Length field. Attackers can declare lengths up to 4,294,967,295 bytes on running dynamic channels, causing StreamPool_Take to reserve memory before body validation and exhaust client memory.
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
Fixed in FreeRDP 3.32.2. Red Hat fixes Red Hat Enterprise Linux 10 AppStream and CodeReady Linux Builder in RHSA-2026:94514. The sources list no fixed version 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 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 3.32.2
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 →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No 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
- 2026-11-03 Threatist record created from CVE-2026-121388
- 2026-11-03 Alias added: GHSA-vrcq-2593-3p64
- 2026-11-03 CISA SSVC decision points changed
- 2026-11-03 Priority changed: MEDIUM → LOW
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94514 · Red Hat
- 2026-11-04 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-2026-121388 · CVE Program
- CVE-2026-121388 · NVD
- FIRST EPSS
- GHSA-vrcq-2593-3p64 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-121388 · 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