FreeRDP Infinite Loop via Truncated WebSocket Frame in websocket_context_read
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: 4 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-835.
Summary
FreeRDP before 3.32.2 contains an infinite loop in websocket_context_read, which does not handle a zero BIO result while payload is still outstanding (CWE-835). A malicious RD Gateway can send a truncated WebSocket frame followed by a TLS close_notify, making a client thread spin and consume CPU until it is killed. CVSS 4.0 scores it 7.1 (HIGH). A public proof of concept exists, and CISA has not added it to KEV.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
FreeRDP before 3.32.2 contains an infinite loop vulnerability in websocket_context_read that fails to handle a zero BIO result with payload outstanding. A malicious RD Gateway can send a truncated WebSocket frame followed by a TLS close_notify, causing a client thread to spin and consume CPU until killed.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- 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
Remediation
Upgrade FreeRDP to 3.32.2 or later. Red Hat rates the issue Moderate, and no fix is currently available for Red Hat Enterprise Linux 7, 8, 9 or 10.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA FreeRDP (FreeRDP) Fixed in 3.32.2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
FreeRDP 3.32.2
14 records Highest priority Priority HIGH 11 HIGH, 3 MEDIUM
Other records, highest priority first
- TI-2026-85092 Use-after-free in FreeRDP rdpgfx channel close handlingPriority HIGH 81
- TI-2026-85091 Out-of-bounds write in FreeRDP proxy via bitmap cache v2 capabilityPriority HIGH 81
- TI-2026-85103 Heap buffer overflow in FreeRDP RD Gateway RPC clientPriority HIGH 77
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | 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 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-11-04 Threatist record created from CVE-2026-121959
- 2026-11-04 Alias added: GHSA-8rqh-cpfg-mwcc
- 2026-11-04 CISA SSVC decision points changed
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · 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-2026-121959 · CVE Program
- CVE-2026-121959 · NVD
- FIRST EPSS
- GHSA-8rqh-cpfg-mwcc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-121959 · 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